I would say Spice & Wolf but you said something exciting
The Melancholy Of Haruhi Suzumiya, high school, comedy, supernatural, not really for everyone but you never know
Fullmetal Alchemist, it's 51 episodes but it is definitely worth the investment
Baccano, fast paced, kind of hard to keep up with sometimes but good none the less
Angel Beats, funny, dramatic, touching, crazy, it's got just about everything
Hellsing OVA, action packed with vampires that don't sparkle
Elfen Lied, something gory and perverted
Higurashi, something gory and fucked up