I used to go on AIM a lot, but that was then and this is now. Now, it's MOSTLY just for RL people. Basically my school friends (9/10 are jerks/never on) and my younger cousin, but he's cool.
I use MSN for you guys, really. I'm on....Always. Because well...You guys rock. Everyone else sucks.
But I have Trillian, but I only use it when I need to talk to AIM people and MSN people. But that's rare.