Has anybody listed Gekkan Shoujo Nozaki-kun?
Because my friend just recommended it to me and...I'm dying...send help XD
I was going through the pages to see if anyone had recommended this yet! I was seriously crying from laughter while watching this XD If you finish the anime and want more the manga is still ongoing and have several subplots that didn't appear in the anime, though at least one of them is now being shown in the Gekkan SHoujo Nozaki-kun Special Episodes.
The rest of my recommendations have already been mentioned here, but I'll mention them again I guess ^^
Fullmetal Alchemist: Brotherhood, Attack on Titan (read the manga!), Stein's Gate, Death Note, Code Geass, any Miyazaki film and Wolf's Rain. If you don't mind gore and a really dark setting I dare you to go and read Berserk. I recommend reading (not watching!) Ghost Hunt as well =)