Information
Wikipedia	The huge encyclopedia that any domain expert (whether it be a useful domain or not ;) can contribute to.
WikiHow	The how-to manual you can edit, with guides for several various projects (many useful, some just amusing).
Information/Games
The Videogame Museum	Archive of MANY old favorite games, with pictures and endings.
Nintendo Land	Great site to find out about Nintendo's video game classics. "Prepare for a nostalgic journey."
Metroid Database	If you liked any of the Metroid series, then you don't want to miss this.
Information/Emulation
RHDN	Large library of documents and utilities related to console game 'customization'.
Zophar's Domain	An encompassing site for emulation in general. Check out their collection of utilities, SPC/savestate archives, docs, and forum. Thanks to them for hosting my utilities long ago.
EmuXHaven	Looks like a good site for emulation related interests.
GSHI	Home to a huge selection of cheats and game enhancement codes, from retro to recent.
RPGD	We can thank them for translating many good console RPGs for us English speakers. Perhaps you've heard of Neil Corlett?
Information/Programming
Programmer's Heaven	Great resource for docs, various systems, and several languages.
GameDev	Game developer resources galore, full of articles and resources.
Code Project	Great development resource where programmers document their projects in articles/tutorials, offering both the final program and source code.
SNES Developer's Corner	Lots of technical SNES documents, assemblers, disassemblers, and ROM utilities. Twas one of the first sites I found with all this stuff.
Emulation Programmer's Resource	Excellent for information on several systems.
BeXXX' SNES Programming Page	SNES Demos, source code, and old docs.
People
Digital Reflections	College friend's website (Chris Moore) with little graphics demos and small games that arise as by-products of his experimentation.
Alpha II Productions	Useful emulation programs by AntiResonance (SPCTool particularly)
Fusoya's Niche	Useful utilities by Fusoya (like Lunar Magic and ZCompress) plus translation goods.
KoroSoft	Site of a Canadian friend.
Qwertie's Oasis	The most helpful SNES docs out there (SNES Knowledge Base!) plus the emulator SneQr.
Rage Games	Interesting old NES hacks and SNES demos, plus old game reviews and Game Genie codes.
Software
Iron C.L.A.D.	A general purpose data editor that unlike game specific editors, uses map files to specify where important locations are and what type of data they are. Although it can be very useful for console game savestates, it technically is capable of being used on anything with fixed locations, as long as there is a map file for it.
Software/Audio
SPC Tool	SNES SPC player and converter
Software/Graphics
vSNES	SNES game savestate utility (can help make maps like ones you see on vgmaps). It's like BgMapper, but newer, more capable, and more user-friendly.
TilEd	Multi-Console tile editor supporting quite a few different tile modes.
TilEd2002	Newer TilEd with freshened GUI (not sure if same author?)
SMC-Ripper	Tis a bit dated now, but it was the first console graphics viewer I used.
IrfanView	Great picture viewer. Intuitive, fast, supports all common and many unheard of file types. Can easily navigate folders with arrow keys, and shows better thumbnails than Explorer.
JPEGcrop	Crop/rotate/flip JPGs with no detail loss.
Software/Games/Emulators
ZSNES	The fastest SNES emulator I know (the one which most of my utilities work with the savestates of, with SpriteView loading colors from them, TileView jumping to WRAM, and BgMapper loading the scene).
Snes9x	One of the two greatest SNES emulators, around for longer than ZSNES. Best of all, you can more than play it, you can get the source to it and find out how the SNES works.
SneQr	This emulator lacks sound and transparency, but it has the one thing I really needed, full debugging ability. The source is also available.
Software/Video
MPlayer	MPlayer is a an open source media player that plays almost anything you have (available for all major operating systems). It's not as GUI friendly as others, but the configurability and capabilities are what really count.
ASF Tools	Processes ASF,WMA,WMV, including join, split, repair, extraction of audio, and my reason for downloading: can convert stupid ASFs into useable AVIs (rids the seek lag and even produces slightly smaller file).
Art/Music
Overclocked Remixes	Great archive of remixed video game music! "Founded in 1999, OverClocked ReMix is an organization dedicated to the appreciation, preservation, and interpretation of video game music."
Videogame Music Archive	Good archive of video game music MIDIs that's been around > decade.
SNES Music	Large SPC music archive of old games
Art/Images/Maps
VGMaps	The Videogame Atlas, with lots of maps of old 2D video games.
Video Game Maps @Ian-Albert	Detailed level maps of few old games - like Zelda LTTP! (overall, seems like an interesting fellow too).
SNES Maps	Hobbyist (Rick Bruns) who has made a few maps of SNES games.
Art/Images/Anime+CG
DeviantArt	Great repository of artist's works, covering a wide range of styles and mediums.
Tinami	This central directory of manga artists is a great resource to find good cg artwork.
The Ultimate Animanga Archive	Site with pictures and music from all the Anime series I have seen, plus plenty of ones I have never even heard of.
Just fun...
The Dialectizer	Fun converter to translate plain ol English inta Redneck, n Jive, n Pig Latin... Fun; just try it.
Games for the Brain	Fun little puzzle/memory games (the Rotate^2 is addictive).