:D  i'm quite fond of Jakob Nielsen, actually, 
and highly recommend his book, "Designing Web 
Usability".

the importance of navigation can't be stressed 
highly enough!  sites that are annoying or 
confusing to navigate you can be sure i won't 
return to!  on that note, i'm quite fond of Anime 
Taro's set-up.  s'too bad that sometimes the 
background doesn't display correctly, but it's a 
gem to navigate and make purchases from.  

(the Animanga pages are also quite nice in that 
regard.)   

oh, and how about these peeves?  freaking tiny 
fonts.  layouts that are screen-size dependent.  
designs that are browser dependent.  (don't do 
it!)  dead links.

i recommend getting a few people using different 
platforms and broswers to check out your page.  

there are services online that can spider pages 
and search for things like correctness of HTML 
and dead links.  very useful; i'm trying to 
remember what they're called.  but they don't 
cost anything to use, and they're *very* helpful.