When it comes to villain types, I really like villains who have a strict code of honor or moral code they stick too, even if the moral code doesn't make sense to anyone else. They don't really have a lot of grandiose plans, in fact they just do their own thing and play whatever side maybe the most interesting for them.
Villains like Joker, who simply doesn't follow any rules and even when he is in a team with other villains, will throw a wrench into things, or even HELP Batman because it's a hell of a lot more fun that way.
Villains like Hisoka who only seek to fight strong opponents for the...err....sexual thrill of it. He may be on the villain side, or may even help Gon and the heroes. All just so he can keep an eye on his future challenges.
Villains like Kimblee, a sadistic Darwinist who takes "Survival of the Fittest" and "To the Victor Goes the Spoils" to a another level. He admires people's strength, both of will and of power, though he see's little worth in human lives...including his own. Everything is simply black and white to him, soldiers follow orders and kill, doctors saves lives, artists create beauty, etc. There is no going back, there are no grey areas. If you do something, you do it 100%. Thus when Pride is willing to devour and steal power from a human, Kimblee betrays him, stating that Pride is a hypocrite: demeaning humans while then happily trying to steal their power. Kimblee's moral code is not OUR moral code, but it is a CODE.
These villains I really, really like. The Blood Knight, The Loose Cannon, the One who goes through Revolving Doors of Heroism/Villainy, they are the most interesting to me. I think I envy them in a way...they are only villains because they live their lives exactly how they want it, without any moral justification or big plan.
