in rank of fun:
Team Fortress Class (TFC) - this mod is based entirely on skill, ping makes very little difference
Science & Industry (S&I) - like TFC but using HL weapons, you capture the enemy team's scientists so that you can build faster. the faster you build, the better the equipment and weapons you have
Counter-Strike (CS) - lots of cheaters, based a lot on ping but still basically a good game
Day Of Defeat (DOD) - sort of like CS but you die in 1 shot no matter what, sorta gay
Front Line Force (FLF) - sort of like CS mixed with TFC, you can take more bullets but the guns are just terribly weak. basically still a cool game though
the other mods just sort of suck.