I like reading random factual stuff that has no bearing on my life, just for the hell of it. Wikipedia is one of the top contenders well known on the internet for making people crawl out at 6AM three days later wondering what happened after clicking link after link. However there are other sites like this that can cause you to lose vast amounts of time, they’re usually wikis but can fall in other formats.
The one I’m into right now is TV Tropes (www.tvtropes.org), it’s like wikipedia except it deals with comic, movie, video game, television, and literature schemes, tropes, etc. In fact it can be a bit more dangerous than wikipedia, because the clever example-driven titles of articles draw you in to clicking and worse yet, a lot of times you don’t know all about them. In wikipedia you’ll often run into a roadblock where you’re only linked to science (or English etc) articles you learned about on the dope or in school, in TV Tropes it’s all about stuff that exists in books you read and TV you watch. And they have long examples sections after the articles, pointing out shows (and various specific places in the show) where it works. And it often also adds in explanations for memes showing various mutations of “Super Prepared” (Batman) and all the characters who have adopted these ideals.
So any other sites you’ve found that absolutely suck your time dry reading links into the wee hours of the night?