Definitely Hetalia, Soul Eater, Inuyasha, Full Metal Alchemist, Bleach, Black Butler, and Death Note! oh and Ouran High School Host Club!!
1. Mahou Shoujo Madoka Magica (or Puella Magi Madoka Magica)
2. Blackâ˜…Rock Shooter
3. Elfen Lied (very disturbing, though....)
4. Black Cat
5. Mythical Detective Loki Ragnarok
6. Darker Than Black
7. Angel Beats
8. Spice and Wolf
10. Corpse Princess
11. The Sacred Blacksmith
Random ones I thought might interest you, since I don't know what you normally watch.
I don't know what type you like but I'll just name all best one's I've watched by genre.
Action+Supernatural: Black Butler: Naruto, Bleach, Fairy Tail, Soul Eater
Romantic Comedy: Ouran High School Host Club, Kimi Ni Todoke (this one is adorable ^^) Toradora.
Other: Death Note, Hetalia
Sgt. frog, shakugan no shana, black butler, hetalia, deathnote, naruto, and others that i forgot
If you like romance and comedy you should watch Lovely Complex, Fushigui Yugui, and Ceres. More into action. Watch One Piece, Ruronoi Kenshi, Black Cat, and Inuyasha.
I really like Angel Beats, you should totally watch it
ive seen a ton that i dont remember....
yu yu hakusho
princess tu tu
ouran high host club
i think there were more, but i cant remember their names...
i only know vampire knight. its an ok anime. i wouldnt say its the best.
My goodness gracious, have you seen Fairy Tail??? Best. Freaking. Anime. EVER!!!! Oh, there's also Kiba, MAR Heaven, and Romeo x Juliet. They were okay.... But not as god as Fairy Tail XD