For my favorite titan, it has to be Raven. Same reasons as everyone else. She's dark, mysterious and when ever she has an episode based round her, its always cool.

Spoiler:
Oh and the fact she brought about the end of the world via her father was also a good storyline for her too.


As for a villian, I'd have to go for Brother blood. There is just some kind of evil, coolness about him. Martail arts expert, interesting powers and a genius. Its a shame there were only a few episodes were he was the main villian. Still I liked his connection with Cyborg which gave them both a storyline together. Anyway, the reason I've put both my favorite titan and villian is because there both too cool to chose from (in my opinion anyway).