I know what you mean. I've played Sins online and we in the DS community set up a thread to work out the schedule. Works wonders.
I wouldn't mind playing Supreme Commander online, but prefer to play with those I know and so usually LAN it.
Yeah, I like playing with people I know better. I've certainly had a lot of fun playing Alien Swarm, but more so when I played a few games with morph.
Though I have to say, these 3 German dudes I just finished playing a few games with were pretty awesome. At right about the end of the last mission, when the nuke is set to go off, one of them says "Run bitches". Lulzy, innit.