I'm so intimidated. You made this thread for anime recommendations, that doesn't mean you can't lie about how many anime you've watched. I doubt you watch anything that requires a bit of thought to enjoy.

I haven't seen these two mentioned, I personally enjoyed them immensely.

Melancholy of Suzumiya Haruhi
Gunslinger Girl

Also, I agree with Elfen Lied being good, but it put me into a depressed state for a good 2 weeks after watching it. It's also gory as hell. And has nudity. So ya... it's a bit of a mindfuck.