Sup!
I play a lot of Natural Selection (unknownworlds.com) which is a FPS/RTS of Marines vs. Aliens.
There are 3 main types of game for it:
NS - typical RTS teamplay; my favorite mode. Each side runs around building resource gathering equipment, shooting/biting/gassing/swiping/mauling each other. The Aliens have 1 starting hive, but can build 3 total. Each hive affords one kind of upgrade chamber (movement, defense and sensory.) Each type of chamber then gives the individual life form a choice from 3 different options per chamber... for example, a Movement has Silence, Adrenalin and Celerity; you don't make sound, you regen your energy faster, you move faster.
CO - "Combat" where each person makes their own personal upgrade decisions. Still a team game, but each person could have completely different upgrades or life forms. Only one hive and no Infantry Portals (just kill the Command Chair), but this does not limit you upgrades. To get upgrades, you get experience by killing or being near killed enemy beings. Each point can be spent however you like, so long as you have enough points to get the upgrades you want. It can be a lot of fun, or totally one sided and quick.
NS-siege - I don't care for this mode too often. It's a kind of map type where both sides are separated for about 5 minutes, usually enough time to get the important upgrades and a third hive going. After five, the main door that separates the sides is opened up automatically. 3-12 (depends on the map) more minutes pass and then a "siege room" opens. Marines and Aliens try to cram in to that room and build chambers or sieges before the other side; who ever takes the siege room almost always ends up winning, but the marines still some times pull off a direct hive assault.
I have also started playing "Zombie Panic! Source" which can be a lot of fun, or really annoying.
Both sides (survivors and zombies) have their differing merits of barricading, smacking, weapon sharing, ammo sharing, seeing in the dark, lunging, blowing things up, etc... It's a game you kind of just have to try playing to see if you like it... of course, a lot of people think it is some how like "Left 4 Dead" but from what I have seen... I think they are very different games.
Also, I mess with pardus.at some times a week. It can be a lot of fun, or really boring. It can be free, or you can pay a yew bucks a month for some premium features. You'd just have to play it to see if you like it.
Peace!
