I prefer fps with multiple classes (eg. a soldier, medic, engineer so and so), that way the game wont get boring too quickly!
Such a game like Enemy Territory, each class has its advantage and disadvantage where teamwork is all that matters. Though I can't say that i'm "undefeatable" in that game, still i ain't a "noob".
Be a field op to direct artillery fire and airstrikes.
Covert op to scout with sniper rifles, steal enemy's uniform as a disguise to open doors and cause havoc behind enemy line.
Engineers are able to construct crew served MGs, arm/disarm dynamites, landmines & covert's explosive satchels.
Medics can heal and revive, either work within a fireteam or stay solo killing enemies. In etPub mod, you can poison the enemy to weaken them.
Soldiers are just great damage-dealers with their mobile mountable MGs, mortars, panzerfausts and flamers.
Great game!