What's the best instant messenger client?

I've heard all sorts of stuff about aim, gtalk, msn messenger, and yahoo messenger...but what's the best im client? Is it just whatever my friends are using, or is there one that's really better...and if there is one that's better, why is it better?

personally I like windows live messenger or yahoo messenger. the reason for that is you can do much more like computer calling and music all from your messenger. but if you just want to type then any messenger is workable...I myself prefer yahoo messenger over any of the others actually

AIM (aol)

I say aim is better t has music camera live chat and it gets updated all the time so theres new things 4 your pro and other stuff