the ads in aim haven't been that annoying to me...I've never encountered any video ads so far myself in aim.
However, if you care, there's an ad-free and very sleek and powerful version of aim express if you just go to aol.com and hit aol instant messenger on the main page...
I think I accidentally found it once, and it locked on the machine I was using it on(was a school machine and it might have been just an issue with that machine) but looked awesome, and then the next time I only found the older aim express which stinks and I got all confused.
But now I realize there's two versions...one which is basically the embedded instant messenging system inside of AOL 9.0(or at least looks aesthetically the same), and one which is the old school cruddy one =P
The more powerful one can do pretty much anything the IM system in AOL 9.0 can other than the superbuddy icons and similar stuff...it pretty much replaces AIM if you want to!
At any rate you should give it a shot anyway...it looks very cool