Quake:

*3Fingers' Unofficial 16-bit OpenGL Miniport Driver v1.47 3/2/99(allows GLQuake & GLQW to use 16-bit color on all 3Dfx cards)
GLQuake v0.97 11/14/97(Windows OpenGL version of Quake1 - requires Quake1 to be already installed)
More downloads here: http://www.planetquake.com/impel/ftpdir/quakeupdates.htm

QuakeWorld v2.3 8/29/98(includes GLQuakeWorld which is the OpenGL version)
More downloads here: http://www.demon.nl/eng/games/quakeworld.html

GLQPlus Utility(sets up your 3Dfx and GLQuake settings and performance tweaks for Voodoo1 cards painlessly)

VIS TRANSPARENT WATER PATCHES (probably the only place you can find them anymore!):

GLQuake Retail Maps VIS Transparent Water Patch(includes VIS Patch utility program)
(requires VIS Patch utility program)
Quake Mission Pack 2 (Rogue) VIS Data(requires VIS Patch utility program)
ThunderWalker CTF VIS Data(requires VIS Patch utility program)
ThreeWave CTF3 VIS Data(requires VIS Patch utility program)
ThreeWave CTF4 VIS Data(requires VIS Patch utility program)
NOTE: I have other VIS patch data files in my library. Drop me an email if you're looking for something not listed here.

Quake2:

AMD 3DNow! 3Dfx Voodoo2 Quake2 v3.20 OpenGL Miniport Driver 4/2/99
Q2 v3.20 Upgrade Patch - 12/1/98(updates any version after v3.12 to v3.19)
Q2 v3.20 Full Install - 12/1/98 (updates any version to v3.20)
Q2 v3.20 Full Install w/CTF2 - 12/1/98(updates any version to v3.20)
Q2 CTF v1.50 Upgrade Patch 1/8/98
Q2 CTF v1.50 Full Install 1/8/98

Quake3 Arena:

*Unofficial Performance Q3A DLLs from ShugaShack
*Unofficial Intel-Optimized Q3A DLLs from BarrysWorld(Intel CPUs only)
(NOTE: You MUST install the point release to use these. These DLLs can increase performance by 5 - 20%. However, they may not work with add-on mods. Copy these DLL files to your QUAKE3 folder. If you have any problems with a mod, delete the files and Q3A will default back to using slower VM code)
Quake3 Fortress mod (Outstanding Team Fortress mod)
Quake3 Classic CTF mod

Half-Life:

*Unofficial HL AMD 3DNow! miniport patch for 3Dfx Voodoo2(please read important note here)
Team Fortress Classic Manual
Half-Life Counter-Strike mod - Awesome mod!
Half-Life Day of Defeat mod - Awesome mod!

Windows Updates:

3D Card Drivers:

IMPORTANT NOTE! I do not recommend beta drivers.

ATI RADEON CARDS:

You can find Radeon drivers at Rage Underground or ATI's website

NVIDIA CARDS (TNT, TNT2, Geforce):

NVidia Detonator4 Drivers(for ALL NVidia chipset cards,I recommend these drivers over the manufacturer's drivers - they'll usually give better performance with more stability)

3DFX CARDS (Voodoo2,3,4,5):

NOTE: Since 3Dfx is dissolving their company, I've mirrored these drivers on my site. More are coming.

Voodoo2 Mis-matchedSLI Cards Patch for 3Dfx Reference Drivers(You can also get additional information on modifying any V2 drivers for mis-matched cards at Devnull's site here...)
Voodoo2 Reference Win95/98 - v3.01.01 2/1/99(I personally think this was the best V2 driver ever written, but it has no OpenGL support so you need the Metabyte WickedGL miniport for Quake3)
Voodoo2 Extended Features Control Panel for 2/1/99 Voodoo2 reference driver(Use this to get clock and VSync control panel with the 3Dfx V2 reference driver above)
Voodoo2 Hacked Win95/98 Drivers for Athlon systems NEW LINK! (Use these drivers if you're having problems getting a V2 working on an AMD Athlon CPU)

NOTE: BETA DRIVERS for all 3Dfx Voodoo are available at 3DChipset.com and X3Dfx

You can also find Voodoo drivers at Reactor Critical and Voodoofiles

Utilities:

General

PowerStrip(Excellent shareware utility that allows you totweak EVERYTHING on your video card including setting different refresh ratesfor each resolution, AGP bus settings and overclocking)
DirectX Uninstaller by ebrink(Uninstalls any version of DirectX - WARNING: Use at your own risk! Please read the instructions carefully!)
UOTrace Utility(use to troubleshoot poor Internet server connections - READ THE INCLUDED README FILE!)
PS/2 Mouse Rate Adjuster v0.4(increases refresh rate of PS/2 mice to eliminate mouse jitter in Quake engine games)
OpenGL Switcher(switches between different OpenGL cards without switching DLLs back and forth)
3D Control Center(switches between different D3D cards for games that can't do it)
Windows 2000/XP Game Launcher(allows you to assign a higher priority thread to run games under giving them more CPU time - FOR WIN2K/XP ONLY)

For 3Dfx Cards

Voodoo2 Overclocker v1.4.00(gives you a tab with clock and VSync controls for Voodoo2 if your driver doesn't - Works with Win2K!)
Voodoo3 Overclocker v3.1(gives you a tab with clock and VSync controls for Voodoo3 - works with Win2K!)
Voodoo Doctor/Glide Switcher(allows switching between Voodoo and Banshee cards for Glide apps)
Creative Labs Glide Switcher Utility(allows switching between Voodoo and Banshee cards for Glide apps)

For NVidia Cards

idGamma(Provide richer colors and a brighter image for TNT cards)
NVidia Win2K/XP Refresh Rate Fix Utility(Fixes 60Hz refresh problem in Win2K/winXP)

*Unofficial drivers are not supported by the manufacturer.