I like CTF, because the strategy and the vast number of awesome levels available for it. DOM can be fun too, because it often has more of a battle style gameplay, but with the action more focused. LRS is great fun because it forces a bit more caution and rewards playing smart more than spamming the space-bar. I've had a few fun Pestilence games, and in some regards it's like LRS, minus the annoying waiting part if you die. Also, Single Player, because there are some really awesome levels out there.