1.  A contact page called "contact-me" or an about page called "about-me".  Just call it "contact" and "about". 

2.  Colophon is synonymous with "powered by".  I hate it. 

3.  Movable Type/TypePad addresses:  Big, long, ugly names that are cut off after a certain number of characters.  http://askpang.typepad.com/relevant_history/2005/04/stupid_editing_.html, http://www.boingboing.net/2006/01/12/new_york_press_on_ch.html

4.  Unnecessarily long folder names/structures:  /Moveable_Type/archives/, /weblog/archive/2005/12/23/368/post-name/

5.  Terrible spelling and grammar. 
"10 websites you should defiantly know about."
Original:  "Dr. Martin Luther King, Jr. Observance - Thursday,  18  January 200 6"
Corrected:  "SORRY FOR THE TYPO... Dr. Martin Luther King, Jr. Observance - Wednesay,  18  January 200 6"
"Of course, they were expected to cheat, their Microsoft." #technology