There are a few games that are particularly interesting, that I will most likely arrange events in if the group gets over a certain size!

For now, these games are:

Magicka
Diablo 2
Median XL (Mod for Diablo 2)
Counter-Strike: Source
Oblivion
Overgrowth
Minecraft
Garry's Mod
Call of Duty 4: Modern Warfare

http://forums.steampowered.com/forums/showthread.php?t=1289845

In that link, you can find various mods and their fixes to work on the orange box engine for Source. This includes Half-Life 2 mods like METASTATIS and SMOD.

There are also instructions there how to make other mods work!

All kinds of mods, including Khan Challenge ( https://sites.google.com/site/magmodd/ ) and KrietoR's PvP mod are examples of mods that could be listed and available :)

Please remember to specify you are the author of the mod, if you are.