We have several in our Mods/TCs page:
Wolfenstein Alien Edition http://www.legendsworld.net/shooter/modaddon#1
Doom - Aliens TC http://www.legendsworld.net/shooter/modaddon#11
Cryis - Predator: The Heat Of The Jungle http://www.legendsworld.net/shooter/modaddon#510
Aliens: Killing Floor http://www.legendsworld.net/shooter/modaddon#8621