Too many to post here, I see a funny video, I save a link to it.
Then some I'm too lazy to type most of the time, some for university, pages of professors etc.
Mostly use Opera's quickstart thing though to get to the pages I visit most frequently, like this weird place here.
But I don't mind having tons of bookmarks, the file is only a few kB anyway, and it synchronizes them between PCs automatically as well, so whenever I want to find some cool video I saw once, I can look at my bookmarks.
My quickstart choices are:
Computer Base
Krawall
GameReport
GameTrailers
The Guild
SimHQ forums
PlayStation Blog
Touch Arcade
The Onion
Zero Punctuation
StudiVZ
Bookmarks