Czar,
Have to side with you on your thoughts. Had a blast at the 150 playing the FPS games, but we may have had the most fun playing CIV4. Some RTS would be great (and I will get slaughtered). Willing to play C&C as long as I have the correct game. (When you mention C&C 3, is that the absolute latest in the series?) COH is also a blast. A few of us play it at the small LANs. If anyone wants to try, how about some Midevil 2: Total War?
In general, I found bring everything and anything to the LAN you think people may want to play. So many games are out there and everyone have a favorite.