Left to right on my Firefox bookmarks:

Facebook
last.fm
EoFF
YouTube
LiveJournal
Bob and George
Diesel Sweeties
Questionable Content
Ctrl-Alt-Del (for the lulz)
8 Bit Theatre
Achewood
Cyanide and Happiness
bash.org (not so much anymore but it's still there)
Speed Demos Archive
Neskaya
Hot Sexy Slashfic
Muxtape

And I also visit Google and xkcd (which I don't have bookmarked for some reason). And Wikipedia, which I have a search box for in the upper right of Firefox. And unoccasionally 4chan (only when I'm completely bored and have read everything else).