It doesn't matter if you do all the error checking in the world, or if you have the most beautiful graphics, if your site or application design isn't usable, it's not going to do well. Get input and advice on usability and user interface issues here.
I just finished implementing the new design for my site http://www.nderson.ca. Let me know what you think!
P.S. Oh, I know it sometimes doesn't fully load up in IE6. I've also heard of problems with IE7. However, since the page & CSS validates and it's a personal page, I don't give a hoot.
Real programmers don't comment their code. If it was hard to write, it should be hard to understand.