I haven't really cared for your typical "deathmatch" style of multiplayer probably since the N64 days with Perfect Dark. I find it gets repetitive quickly and boils down to everyone using the same weapons in the same places at almost the same time every match. It certainly doesn't help that since Modern Warfare released, all the weapons in online FPS games seem to be the same: a half-dozen variants on a submachine gun/assault rifle, 1 sniper rifle, and a rocket launcher. It just gets dull fast.
That said, I have recently gotten into playing Resistance 3's multiplayer, which is severely unbalanced right now (the Atomizer and shotgun are pretty overpowered) but very fun. I think the key there is that you have a wide variety of weapons with these crazy alt-fires that change how you react to a given situation. For instance, the Atomizer is basically a flamethrower when you get down to it that shoots electricity instead of fire...that has an alternate fire that releases a singularity that drags foes out of cover. Then there's the Rossmore shotgun that can (when leveled-up) shoot fire and has an alt-fire that releases an incendiary grenade. Then there's old standbys like the Auger, which allows you to shoot and see through walls like Perfect Dark's Farsight with an alt-fire that places a shield that repels incoming fire. I could go on, but it all leads to a much more fun experience for me, despite the multiplayer being pretty standard FPS.
Incidentally, I thought Bioshock 2's multiplayer worked pretty well as well, since you had all these players with all these plasmids running around, and you could collect XP doing tasks other than shooting people. Uncharted 2's co-op was really good, though it's Deathmatch modes were pretty "blah".
Oddly enough, the multiplayer I thought I really would enjoy in Killzone 3, because of the innovative "Warzone" and "Objective" modes? Eh, all the weapons feel more or less the same and players on both teams more or less look the same, if you can see them at all. Fun, but not spectacular.