Games & Other Fun Stuff:
Runescape : A fantasy adventure game
Pen-paper : A database of role playing games

Snopes : inquiry into urban legends, common fallacies, misinformation, old wives' tales, strange news stories, rumors, celebrity gossip, and similar items.
Mythbusters : a website for the Discovery Channel show Mythbusters includes quizzes, games, videos and results of previous inquiry.
Funtrivia : Like the title says: Fun trivia. Also, game and quizzes.

Sharing Machine Comics : A hub for the webcomics Married to the Sea, Toothpaste for Dinner and Natlie Dee
Fluff in Brooklyn : A selection of webcomics and podcasts

Magazines and Zines online:
Rookie Mag : A teen magazine for teenage girls, by teenage girls, updated daily with advice, music, books and style.
The Onion : A farcical, funny newspaper full of articles which highlight social commentary
The AV Club : From the people who brought you The Onion--a website focusing on arts and culture, featuring television, video and book reviews
The Source : Hip-hop music, culture and politics
Twist Magazine : Style and fashion for the modern teen girl
Thrasher Magazine : All skate culture, all the time
1UP : An online gaming magazine, featuring reviews and cheat codes