One more pet peeve of mine: websites with giant non-scrolling banners at the top of the page. Thanks for wasting my screen space just so you can show your stupid website logo. As well as the pixel wastage, half the sites can't even make their banner stay still, it wobbles slightly as you scroll and it tries to reposition itself. Or, it breaks page scrolling - page up/page down will skip content hidden under the banner.
And while I'm moaning about the web of today: Also annoying are the sites that hide/shrink the banner as you scroll down the page, but make it pop back up as soon as you scroll upwards. If you accidentally move slightly too far down a page, you shift back up a row or two to catch a missing line of text, only to find a banner popping up and obscuring the bit that you specifically tried to view. Argh!