Cool Stuff

VidyaScape - Free 2007 RS Server
Neocron: Evolution - One of the first FPSMMORPGs, community ran, completely free
WoW-Mania - WoW Classic Free Server
GZDoom - Definitive Singleplayer Source Port for Doom 1 & 2, supports the most mods, free
Zandronum + Doomseeker - The definitive way to play classic doom multiplayer, supports lots of mods, free
SWAT 4: First Responders - an overhaul mod for swat 4 that adds a ton of more modern content