Xanxus: Very obvious reasons. Though I Like his younger self
Rokudo Mokuro: He is just to beast for words to describe!!
Daemen Spade: Mokuro solo'd him, even though it was a trap to steal his body. His new body was beast as hell!! His attitude, too amazing! He should have hated Primo, but didn't. He continued to think of him as a friend, for that, he is most definitly a favorite!
Mammon: Just...idk any words to describe it!! His "present" form is too OP!!
Hibara: No words actually needed for this, but his fight against the Phantim Knight was a fave.
As you can see, I like the Mist rings lol
Takeshi: had one of the biggest one shots in the series...his Epic Fail was a bit funny though lol. He was a very good character though. But he was like the one shot shield, getting one shotted by Karou nearly dying if not for Byakuran. Really nice comeback though!!