AIM plagues you with popups and ads. I use it to communicate with, of all things, iChat AV. I tried iVisit and Triillian, but AIM despite its defects manages to work with Apple users of the other side, so I don't really have any choice, yet.
When AIM starts it fills your desktop with huge annoying windows, even starts noisy clips. What a pain!
I just found a way to keep it to its main windows and not overflow all over my screen: AIM Ad Hack by Cuban-Aftermath software. Great!
Anyway: video for Skype, quick!