I have a list of the most annoying ads.
Gifs: Especially repeating ones.
DKTF: I wouldn't mind it as much if it weren't for that annoying sound it makes (and since I listen to music, it's disruptive).
Not to mention extending the page's length. Which causes me to pick something I didn't want (9 times out of 10 it's the ad itself).
Videos: Unlike gifs, you can't just avoid them by reducing the page size (the page would ignore gif then).
With videos, not only do you have to turn it off. But if you don't, then you have repeating audio playing.
Rio 2: I'd hate to see the guy who thought placing an unavoidable ad in the middle of the page was a good thing.
Sure, there's the close button. But I've had times where it didn't work.
So I've had to stop everything I was doing in order for it to go away.