All Progressive ads. Seriously, Flo was mildly funny when she first debuted, but it's gotten really old.
Pandora shows some rather obnoxious ads. One is for some Microsoft program that allows people to collaborate over the internet. A good product, I'm sure, but the chick they hired to do that ad is annoying as heck. She's a stuck-up b****, and I assume that's supposed to be funny, but it's not.
The other one is for a local hospital. It's one of those ads that companies do for some reason, where they brag about how awesome they are. And at the same time, telling you very little about what they do. This one, in particular, brings out all the cliches like "we are never standing still" and "making healthcare healthier." Which, unless other area hospitals have a stated goal of making people sicker, means nothing to the listener.