Crap, they all took Steins;Gate, Bebop, Champloo, Monster, and Death Note. lol
My next highest is Clannad. It's easily the best slice-of-life anime out there, capable of making people both cry and laugh their ass off.
Close second is Mushi-shi. It's completely standalone each episode, with the exception of the MC. It can either be the most boring or the most awesome anime ever, depending on your tastes. It's closer to the latter for me.