Who's the better DBZ villain?!

Unpopular opinion: Majin Buu.

He's just a giant package of effective elements that no matter your preference in villains, you'd like one incarnation of his transformations.
He brings something to the table that other DBZ Villains lack; development and change. I've said it before that each villain works for their saga and are great in their own way. However, it's Buu that actually changes for the better. He learns through others that what he does is wrong and makes a genuine attempt to change. I just find something very touching about a monster who was designed to hurt and destroy display humanity and choose to follow his own path rather than what he was designed to do. We've seen this with various media like The Iron Giant, Bastion, and Frankenstein etc...The scene with Buu and the blind Kid was one of Dragon ball's more sentimental moments. The blind kid couldn't fear Buu because he was unable to see. Buu then heals the boy in attempt of install fear into him, but is confused when the boy was thankful.

Buu was never really "evil"
he's like a child. He quite literally does not understand that killing someone is bad. He doesn't understand it. It's all a game to him, or a source of candy. Only when Mr.Satan and Bee got shot he realized that killing is bad. Because he was about to lose a friend who tried to help him. He's just a villain with unexpected layers to him. I think the buu saga gets a bad-wrap for being so over the top that people forget that scenes like that exist.

It's his other incarnations that I can appreciate his villainy. Each transformation is totally different in how it's designed and acts. His behavior is always unpredictable. I find that more menacing then foes like Frieza and Cell who, while they are evil, can be talked to/bargained and somewhat reasoned with. That's not relevant with Buu because he's just going to do what the hell he likes. He's not interested in world domination or universal destruction. It's about having fun and lolz. There's a darker meaning to this because as humans, we've all got the capacity to commit acts of violence for the sake of violence. Some people, like what the Dark Knight said, just want to watch the world burn for giggles.

I find it remarkable how a villain can go from being so goofy to not being able to eat candy anymore to outright genocide the human race on mere suggestion. He's not what anyone expects him to be. It's Toriyama at the height of his creativity. The ultimate doomsday weapon designed by Bibidi is a silly fat genie who puffs like a steam train when he gets angry! That's brillant! People forget that Toriyama is most and foremost a gag artist. He likes the silly and goofy. It's why the Buu saga is very different from the more serious-paced previous sagas. Buu brings elements never seen before, his gag-magic, rubbery body and weird fighting style. He could turn the powers of our heroes against them and use all his victims strongest assets! From power to technique to even their own intelligence and memories! He's constantly evolving as antagonist by the way His transformations further increase his malice and threat to our heroes.  That unpredictability is by far his strongest asset and kept the saga from derailing from pacing and plot-devices.

For me. It's gotta be Majin Buu.