That said, who's your favorite hero or villain? Who's your least favorite?
My favorite hero is either Batman or Spawn. Both are pretty similar in general theme, and both suffered from the "comic becomes dumb" thing: Batman has a son for example, and Spawn kills God and Satan. Kinda silly. Both of them are pretty badass though, which is most obvious for Batman. Spawn's popularity waned super hard after the movie bombed at the box office but that doesn't matter to me. The ultra-violence in Spawn was kind of a big thing for its time, too. Spawn & Batman even teamed up once but I think that comic was extremely terrible or something, I dunno. Honorable mentions to Terry McGinnis, aka Batman from Batman Beyond.
As far as villains go, you really can't do better than the Joker. I have a feeling this is going to be repeated over and over in this thread. I don't think I even have to say why the Joker owns: it's just public knowledge at this point. Comically, both Batman and Spawn have highly similar villains too. Batman has the Joker, and Spawn has the Violator. The Violator is basically the Joker, but demonic instead. His relationship with Spawn is a lot more violent and twisted than the Joker & Batman: for example, the Joker may try to kill Batman, but he respects him. The Violator has no qualms about killing Spawn. The Joker sort of has a villainous code of ethics, whereas the Violator would literally burn the world given the chance.
Other cool villains are Mister Freeze (Batman, of course) and Carnage from Spiderman. Mr. Freeze was actually really, really, really stupid in the past (so was Batman, though, even if Adam West was aces) but Batman: The Animated Series completely reworked him. The episode Heart of Ice is one of the most critically acclaimed animated features of ALL TIME. Go watch it if you can. It's worth it.
Carnage is cool because he is chaos in its purest form. Venom, Spiderman's biggest and most well-known villain, is relatively sane and at times even helps Spiderman. Carnage is.. well, carnage. He's as vicious as they come.
Honorable mentions for villains: Man-Bat, Ra's al Ghul, Catwoman, Angela (Spawn), Red Skull (Captain America/The Avengers/etc), and Deadpool.
Heroes I HATE are the X-Men (ALL OF THEM), and Superman. Oh, and let me get this out of the way: no one likes Aquaman either.
The X-Men have never appealed to me. I don't like the X-Men themselves, I don't like their villains. None of them interest me and while the movies were entertaining, they were entertaining because they were decent films, not because they were X-Men films. The animated series was pretty cool when I was a tiny baby (and admittedly, it has a cool intro theme), but the whole X-Men universe has always struck me as kind of dumb and hamfisted. That goes for the Marvel universe in general at times, where there are characters like Galactus or Dark Phoenix who are basically gods yet still somehow get beaten by a Canadian alcoholic in spandex.
I hate Superman. I really, really hate Superman. He is my most despised character in all of pop culture. "Grey area" heroes and moral choices get sort of campy and boring at times, but Superman is the opposite: with the exception of a few certain offshoots/crossovers/side-comics, Superman is so good it hurts. It's laughable. You know how cheesy the original Batman was, with his 50's-style code of ethics and such? Superman is like that, but has never been updated morally speaking for the modern day. He is also invincible. He basically can't die unless exposed to kryptonite. Supposedly kryptonite is super rare, yet every villain has access to it (even the Joker when Superman gets involved with Batman stuff). His powers are so boring in their, well, overpoweredness that they literally had to invent kryptonite just to give him a weakness, and even then he's still ridiculous. He can't be harmed by conventional means, he can survive in space, he can survive deep-sea pressure, he has laser eyes, he's the strongest thing ever to exist, etc. Some of the comics even state that he's faster than the Flash, a character whose ENTIRE POWER IS TO BE FAST. Superman is like something you'd come up with when you were five years old and arguing about playtime with your brother:
"I shot you!"
"Yeah I did!"
"Well okay but I'm immune to bullets."
"ALSO I HAVE HEAT VISION AND CAN PUNCH YOU INTO ATOMS I WIN."
Batman and the Joker have a back-and-forth relationship when it comes to who's cooler. They work off each other, and one couldn't exist without the other. When it comes to Superman, every one of his villains is more interesting than he is.
Anyways, your turn, little piglets.