I'm not usually one for Anime, but I've been hearing a lot of good things about this one, and all the episodes were available free online, so I thought I'd give it a shot.
Woah. That is some compelling stuff. Consider me hooked. I'm not necessarily sold on any of the characters yet (Eren in particular feels very cliched and annoying to me so far), but the world they've created makes me immediately want to see and learn more, and the Titans themselves are super freaky.