Some other things I hate:
1) Guesswork navigation. I don't want to have to mouse over arbitraty symbols to see where each button goes. The home button should say "Home," the photos button should say "Photos", etc.
2) Improper use of backgrounds. A background image on a website is a dangerous tool. Some repeating tiled backgrounds can be effective, but most of the time I just see a large photo that repeats over and over, which can be annoying. If you must use a large picture, try the CSS no-repeat tag, and use photoshop to tone down the contrast.
3) Background music. Need I say more? I often browse the web while watching TV in another window, and there is nothing I hate more than my web browser drowning out my TV. If you must have music, have it off by default and use a link to turn it on.
4) Flashy animated GIFs. The only thing worse than Flash. One or two for dramatic purposes it fine, but I don't want to see
this.
5) Bad Mouseovers. If you have a mouseover on your site, make sure that a) the image and the mouseover image are the same size, so the rest of your site doesn't all shift around when I mouseover, and b) you preload mouseover images, so I don't get red sqaures or a blank image when I mouseover.
6) Page Transistions. Yes, I know I can turn them off, but for those who don't, it's just a waste of time. (oh, and I am equally opposed to transitions in Powerpoint, but that is another rant).