These are terribly unstable on OS X... and I don't know why.
There's always Sequel Pro (the successor of CocoaMySQL): http://www.sequelpro.com/
+1 for Sequel Pro. I have been checking this out for the last little while and it has been pretty solid.
I tried the GUI tools. But what I love about the web interface is the ability to CTRL + F anything on the page. And I can also "copy" any text I want in it.
http://dev.mysql.com/downloads/gui-tools/5.0.html