Trillian is awesome for the most part. I found the email with the download link again and it's still a little buggy. I wouldn't except a release this year. There are still a few to many crashes. But when you take out the bugs, it's the best im client ever!
Well IMO the best IM is the one your friends are on otherwise I really like MSN messenger and I love Skype (yes it has IM capabilities). I downloaded Trillian a while back, and it really wasn't that great...
Trillian. I use the latest version right now (not Astra, it's not out yet), and it allows me to connect to pretty much every IM service out there, and isn't loaded with ads or has a GUI that takes up half the RAM
Well, it's all down to which IM client your friends use and personal preference, I suppose. I, personally, have always used Windows Live Mesenger. I have also used Trillian, for multi-protocol purposes, but now have no need to use it. And I have tried AOL Instant Messenger too.