2. One Piece
3. Naruto (when it's not talking about loser Pain)
4. Deathnote (god that series was amazing)
Also, Kannagi, Claymore, Elfen Lied, and Full Metal Alchemist are all equally good so ignore my numbers (they mean nothing) all of them are interchangeable in how much I enjoy them.
And yes Kannagi manga is better than anime imo b/c theres more in the manga, the anime cut short (though was pretty faithful to the story while it kept going)