I watched a few episodes of this anime called Ga Rei Zero a while back, I wanna finish it someday...
It's got supernatural stuff all over it, and a bit of gore and stuff, but nothing to Elfen Lied. Also, a bit of yuri service, if you're into that.
Has anyone seen Last Exile? I heard that was good too.
i've never watched cowboy bebop
Also, that manga someone referenced a few pages back is TOO. EPIC. You NEED to read it, it's so awesome.
IIRC, there was an anime adaptation too.
And re: Fullmetal Alchemist, FMA: Brotherhood follows the manga better, if you're picky about that. I also hear it's very different from the original FMA.