This one's a little less geeky than my usual fare, but I had to include it because it's a really good site. Hulu features free videos. Sure, there's ads here and there, but they have TV shows, full movies, and clips. All that Saturday Night Live stuff you can't see on YouTube anymore? They have tons of SNL clips. Your favorite Daily Show and Colbert Report clips? They have that too. Excerpts from E3? Yup. Want to watch Ghostbusters, or Monty Python's Meaning of Life? They have the whole movie, and a bunch more. Full episodes of Heroes, or Firefly? You get the idea.
You don't need a login unless you want to watch NSFW stuff, and sign up is free.
Unfortunately, Hulu is only available to US residents, according to their sign up page. But hey, if you're in the US, and you want to watch something, check it out.