Link Everything
Few things annoy me more than seeing a reference to something I want to find out about and being unable to jump right to it. That's the whole beauty of the web...

Links should make sense
Many corporate sites (especially those created by and for the entertainment industry) suffer from two related problems: overuse and misuse of graphics. Half of these sites look like the graphic design dropouts hired by these companies simply scanned in a publicity photo and then changed it to an image map so they could create indecipherable links to pages with more 300k .GIFs and goofy contests with slim chances at pathetic prizes.

Every page should tell.
Every site has a finite number of pages (at any given time) and every one of those pages should have a single, specific reason for existing, and an obvious path to it (if not a direct link) from the home page.

Content for content's sake, not technology for technology's sake
People don't revisit a site to see spinning stars or cool frames. People go back to a site either because its material has been updated, or because they didn't catch everything they wanted to the first time. Too many webmasters are too busy showing off bells and whistles to say anything of substance (for more thoughts on the subject, see the Suck column And the Bandwidth Played On). These features not only add little to a site's content, and slow access times dramatically, but also exclude users who don't use the most up-to-date beta-test browser with crufty pre-alpha plug-ins from multimedia vendors.

Java...we'll see.
A challenge: let's say there are two browsers on the market, exactly alike, except for two factors: one is free and lacks Java support, and the other costs $70 and supports Java fully. Point me to a site that would make someone want to spend the extra seventy dollars for that browser, and we'll use Java (provided it can contribute to the site in some way).