Video Recording Edit
FRAPS What you want if you want to record fullscreen PC games or any application that uses DirectX or OpenGL. For $37 USD, you'll get an application that will let you record lossless video at full size and full speed, benchmark your ingame framerate, and let you take screenshots in different formats, all at the touch of a key. Make note that the videos you'll be recording will be huge in file size, so make space for them. There's a trial version available, but don't bother with it. It'll put a watermark at the top of your video and it's limited to recording for only 30 seconds at a time.
Dxtory Like FRAPS, but Japanese. This has several interesting features that FRAPS doesn't, such as the ability to use arbitrary codecs when recording instead of solely a custom built-in codec. Being Japanese, it costs ¥3,600, which makes it cost roughly the same as FRAPS, depending on the currency market.
Camtasia Studio This is the fancy program HyperCam wants to be. They give you a 30 day trial period, and sometimes people even pay 300 bucks for the full version. It has some pretty nice features, like auto resizing the capture area to any window you select, and it's easy to adjust things like framerate, audio quality, and codec. It also comes with an editor that's akin to a less buggy, output unlocked windows movie maker.
HyperCam2 exists, and is a free download now. Someone please add more helpful information about this here. [HyperCam2 has a confusing bug where framedrops will screw up the replay speed of your video unless the option to display a recording rectangle is unchecked and the option to make that rectangle blink is checked. -Thanks tonberrytoby.]
VirtualDub VirtualDub is better known for its editing capabilities, but it's also great for screen recording.
Open Broadcaster Software is better known for its streaming capabilities, yet it includes the fantastic ability to record locally with x264 set to a bitrate of your choosing.
ShadowPlay comes with more recent Nvidia cards (basically anything 600 GTX or higher, although some laptops with 600M GTX cards may be excluded) and is a great way to encode slightly lossy video with your Nvidia card. Be warned that there are some issues you should be aware of.
Video Editing Edit
AviSynth A frameserver, a scripting language, and a non-linear editor. Avisynth is just awesome. This is what you should be using to edit your videos, and it should be the only thing you need, since you can playback your edits without re-encoding and you can feed your script to an encoder to get your final video. Pretty much anything you want to do with your video, you can do it with Avisynth. It can also simplify your workflow and make it more efficient, as you can make a template for edits you frequently make. There's a bit of a learning curve, but there is extensive documentation on how to use it on the site's wiki, and the installer comes with a few example scripts you can take a look at. AvsPmod, below, also has an extensive script wiki in the Help section that is often considered a little more clear than the official wiki.
AvsPmod A continuation of the fantastic AvsP. If you want a GUI for Avisynth, this is as close as it gets, and it's pretty damn good. Some favourite features are filter name autocompletion, the ease in applying trims, and the ability to use sliders to see immediate changes when tweaking settings like color and contrast. The AvsP site has a flash tutorial to get you started, plus extensive documentation on how to use the program's several features, so there really is no excuse not to use it. To top it off, there's even a built in encoder, so you can use this program from start to finish.
Avidemux Avidemux resembles VirtualDub in many ways (its UI, filters, etc.), yet it has several features that VirtualDub does not. For one, it's multi-platform. There are versions available for Windows, Mac OS, Linux, and PC-BSD, so nobody gets left out this time. Also unlike VirtualDub, it can export with several different codecs and containers. Its website has an extensive wiki on the program's features and how to use it, along with several guides and tutorials. If this all sounds good to you, I suggest you give it a try. Except on Windows, where it's not a stable enough build to use right now. (Latest versions show marked improvement, however, we might want to reassess this one -JamieTheD)
Windows Movie Maker Windows Movie Maker is the only free GUI based Non-Linear Editor, which makes it pretty remarkapfffffhaahahahahahahahaasdfjkl;asdfjkl; sorry, couldn't help myself. Movie Maker is a buggy, restrictive pile of shit and you shouldn't use it. It's not even worth describing why, just don't. If you're using it for its effects, they're easily replicated in other, better programs. If you decide to stick with it and want help with it, I suggest going to the site linked above. If you ask about it here, the only response you'll get is use something else.
The Windows Vista/7 version of this, however, is tolerable. Not great, especially when compared to AviSynth or Avidemux, but tolerable. It only encodes in two formats, MP4 and WMV (the latter being a Bad Idea), and it's still fairly restrictive, but it can manage passable 720p or 1080p encoding. It's still preferable to use something else, but it can work, it can handle two or three audio tracks at once plus the video itself, and if you know how it scripts things, you can make more effects/fades/whatnots. As mentioned, though, it's definitely not a preferable option.
VirtualDub VirtualDub has its uses for basic video editing, but it's better to view it as a swiss army knife. It can do a lot, but don't expect it to be the end all video editor. Since it lacks transitional filters, it's best used in conjunction with AviSynth. The FFInputDriver plugin is useful plugin, as the stock VirtualDub normally is able to open *.avi files. It has a good built-in encoder.
Video Muxing Edit
My MP4Box GUI An alternative to YAMB, as YAMB is no longer developed and hasn't seen an update since 2009.
YAMB YAMB, or Yet Another MP4Box UI, is a useful program that lets you mux video and audio streams to an .MP4 container with an easy to use UI. It can also extract streams from different containers, as well as several other features.
MKVToolnix A set of tools used to create .MKV files. It includes mkvmergeGUI, which functions similarly to YAMB in that you can easily mux several streams or subtitles into a single file.
MKVExtractGUI-2 The opposite of mkvmerge, this lets you easily extract individual streams from an .MKV file.
Subtitle Editing Edit
Aegisub A subtitle editor made for making anime subtitles in mind, but don't let that deter you from using it. It's multiplatform, very rich in features, has an intuitive and easy to use GUI, supports Unicode, and can read and output several subtitle formats. The website also features a manual if you need help getting started.
Notepad If you want to be one of the cool kids and kick it old school, all you need is a copy notepad and windows media player 6.4 to jam out them sweetass subs.
Audio Recording/Editing Edit
Audacity Pretty much the go-to audio recorder/editor these days. It's free, supports several audio types, has a bunch of guides written for it, and it's pretty easy to use as far as audio editors go. There really aren't many reasons not to use it. Make sure to get the beta version if you want all the latest features.
GoldWave If Audacity doesn't do it for you, you could always give GoldWave a try. It has a pretty neat interface and it's incredibly feature rich, but it's a shareware program, so you'll need to purchase it if you want to unlock its full potential. However, you should still be able to do whatever you want to do with the evaluation version.
The Levelator A pretty sweet program that you can use to level out audio between commentators and background audio. Just dump the audio file into the main window and let the program do the rest!
Virtual Audio Cable You might need this program if you need to perform complicated audio recording scenarios, like recording game footage and audio as a separate file from skype audio while feeding the whole to a stream for instance. It takes some tinkering to use and its interface isn't exactly easy to figure out. The demo is essentially useless, so you'll want to pony up 30$ to use it.
CallGraph If you just need to record a skype call then CallGraph could be just the thing you need. It's an easy to use plugin for skype that will record the call in a decent quality .MP3 and its basic version is completely free.
MeGUI MeGUI is an incredibly powerful video encoder. It has a massive amount of features such as multiple codec support for video and audio, presets, avisynth editing, deinterlace suggestion, auto updates, and much more. It's only "fault" is that it's a little hard to work with at the start, but we have many guides available that will let you get the hang of it.
Zarx264gui It doesn't get any easier than this. Pop in your video and this program will make an avisynth script for you. From there you can pick your numbers or presets, press encode and it will do the rest. You'll end up with video encoded with x264, audio encoded with Nero AAC, all muxed into an MP4 container. Know x264 inside and out? There's a tab where you can edit the command-line directly. Overall a very simple and solid encoder.
RipBot264 Another very solid encoder with a lot of great features. RipBot's advantages are its easy to use interface and its built in Avisynth editor. It also has support for presets, though the ones included should be all you need. It'll tell you which programs it needs, but downloading Avisynth and the latest version of CCCP should cover it.
Hand Brake Hand Brake isn't my favourite encoder, but the advantage it has over other encoders is that it's multiplatform. You can install it on Windows, Linux, and Mac OS, so it makes a pretty good combo with Avidemux. Its interface isn't the greatest, but it doesn't take long to figure out and it gets the job done, so it's worth checking out. The website also has a user's manual, so you can check that out if you get stuck with something or you'd like to know how to use it better.
CCCP - Combined Community Codec Pack [ Last Update: March 9th 2014] Not a codec pack as much as a combination of Haali Media Splitter, ffdshow tryouts, VSFilter, and Media Player Classic Home Cinema with good configurations. You'll be able to play any modern video file with MPC, so leave VLC for the odd formats that no one uses anymore (or don't use it at all).
Lagarith The current recommended lossless codec. Use this codec as an intermediate to edit your video before making your final encode to prevent quality loss.
Image Editing Edit
OptiPNG When it comes to compressing SSLP images in PNG format, OptiPNG is one of the best programs around, and is an invaluable tool for the average SSLP to cut filesize and page loading times.
Irfanview An excellent image program that has an incredible amount of useful features. Notable ones include opening almost any image format, basic image editing, batch resize and rename, screen/window capture, and plugin support.
Krita , while more of a digital painting app, nonetheless has a pretty low CPU/RAM footprint, and is good for the more artistic, paintery image editing you may want for making your update images so pretty. There's a paid for version with more features, but only use that if you either want to double up with Digital Artwork, or want to say "Thank you" to the nice folks with the nice tool.
Paint.NET A really nice MSPaint replacement that is feature rich, easy to use, and includes plugin support.
GIMP The go-to free Photoshop replacement. However, its GUI isn't that great and it's slow at handling complex tasks.
ImageMagick A very powerful command-line image editor. Once you figure out how to use it, you can do some very cool stuff with it. Read the extensive documentation on the site to find out how.
MediaInfo A really handy program if you need to know information about a video file. Once installed, all you have to do is right click on a video file and click MediaInfo. It'll give you the skinny on the bitrates used for the video and audio, dimensions, length, format, codecs used, etc. You can even choose the way it presents the information to you. It's built into the latest versions of Media Player Classic nowadays, and it's included with most encoding programs, but I like keeping the standalone install just for the right click menu option.
RightLoad An essential program for anyone in need of batch uploading a ton of screenshots. Has an easy to use interface, right click menu options, plugins for multiple image hosts, options for adding tags for easy posting, and a whole lot more. Even if you aren't uploading a ton of screenshots, it makes uploading images to just post anywhere really easy.
Rad Video Tools If you have cutscene videos that are .BIK or .SMK files, this program will let you convert them into easy to edit .AVI files.
QTIndexSwapper Use this if your videos won't play until they completely buffer on your own hosting. It will move the index in your video file so flash will stream it properly. Requires Adobe Air, which is also free, so it's no big deal.
MSI Afterburner is a graphics card overclocking utility that happens to have a screen-cap utility called Predator attached if you own an MSI card. Since we're not sure whether Predator is any good, we've left it here in the Misc section.
Capture2Text is a useful tool for SSLPs, as sometimes, you need to transcribe text from a game, but... The game has no ability to copy-paste text. This, while not perfect, will at least save you some time, recognising text and transcribing it. It has the ability for quite a few languages, but only English, German, French, Italian, Spanish, and Japanese are default. Which, honestly, is mostly fine for SSLP purposes.