Netscape Enhanced Glitz Overload. Too many images that take forever to load that could easily provide thumbnails. Useful information is often buried in hype. There should be clever load balancing to redirect you to a less loaded mirror, or one closer to your net-geographical location. Too many people don't use references, so you can't look up their sources.
Many web pages are hard to navigate because of all their bells and whistles.
There seems to be no standard for searching through forms. Forms are clunky. I should be able to bring up my own editor when filling out some dippy form with a big block of text. You should be able to find out the size of something before you commit to downloading it. Too many people are worried about porn on the internet and not enough are worried about these issues.