To bump yet again, some free Source mods that we could all get together in are:
Eternal Silence - My favorite, though few play unfortunately. Hot outer-space dog-fighting followed by sweet control-point action in giant spaceships.
Different classes, variety of weapons and ships to pilot.
Zombie Panic: Source - A fun mod, start as a survivor, and try to survive zombies. After you get killed, you become a zombie hunting the people. Weapons are lulz-worthy. Not quite like L4D, supports more people, and (last I knew) there are no super zombies. Has a good number of people always on.
Age of Chivalry - Castles and knights everywhere, pretty much. Several different classes and game modes. Played a fair bit as well.
NeoTokyo - Had a ton of hype. Played it a bit after release, and it was pretty cool.
Post: thoughts, opinions on these bad boys, and post suggestions of other baller games we could run.