I always loved the crazy ones. They always keep the anime interesting. The only type of character I highly dislike, is the shy ones. Especially when it comes to romance, or romantic comedy.
I like characters that struggle to achieve something and not characters that are automatically perfect at every thing they do. that combined with a "Never Say Die" attitude, that's great.
This is hard, I love Ryuusei Date who's the most hotblooded Super Robot pilot out there that's still cheerful. Excellen Browning who's overly cheerful and promiscuous. And Kyousuke Nanbu who's the stoic guy.
I've always liked characters that are quiet and soft-spoken characters that have some sort of twist in their personality. In anime, that quality is usually pervertedness or tsudere-ness, so I just chose pervy.