I’m using WP since ever. In my oppinion the best CMS the web has ever seen. Here is the list of my favorite themes and plugins. 
Maybe you’ll discover something you’ll like too.
Theme
Weaver my all time favorite! Love this theme!
Plugins
Foxload more a toy than a tool, but I love it. Puts a Firefox button in your sidebar.
jQuery Colorbox nice if you have photos to share.
Simple Local Avatars – just neat
wp-Monalisa great tool! Couldn’t blog without.