Who is your favorite/ least favorite villain?

When it comes to villains, we always have strong reactions, to the positive and negative. Who is your favorite and your least favorite villain?

(Villain is a broad term, so just use it as you may.)

My favorite: Doflamingo (I'm sure you're all really shocked.), with a close second by Sir Crocodile and Rob Lucci
Least favorite: Spandam (easy choice), but Wapol is a close second