Websites that resize my web browser window, specifically Gears of War. They really bug the shit out of me. Not only does this site resize the window but if I have the nerve to resize it back, it then promptly resizes it down again. So a big thanks to the fuckwit who implemented that.
However, as always, there are ways and means to avoid should fuckwittery. Using the Web Developer Toolbar in Firefox you can simply select Disable / Disable JavaScript.
Tada! No resizing…
…erm, unfortunately disabling JavaScript permanently does break things like Gmail… oops. A greasemonkey script would probably be the best thing to do in this case.