While not on the scale of Thanatos or Darkseid, Hitler’s personal protege the Red Skull is pretty fuckin’ evil! And at least he aspires to be evil on the scale of Thanatos or Darkseid! 
If the entire universe is distroyed, everyone dies, so I would have to go with…
Fredric Wertham
Anyone who ever tried to do away with Tintin.
I second Kid Miracleman. He defines Evil Villain. With a capital E-V. He allowed his abolute power corrupt him abso-friggin-lutely. This was once a good guy who followed the path of greed and power to such lengths that he destroyed the entire city of London. Pretty much, just coz.
Like Tripthicket said, “what was cutting-edge depiction of ‘realistic’ evil in the mid-80s is now much more likely to be the norm”. But I don’t think this takes away the power of Miracleman #15. It punches you in the stomach. Everything since is child’s play.
Technically speaking, he did do it to save Earth from nuclear holocaust.
And…should we specifically not count Manga villains in this? I mean, those guys can get pretty damn crazy, universe-destroying, true-love-crushing, tentacle-fu-ing eeeevil.
Yeah, he isn’t evil. He’s just more capable than most of coolly weighing pros and cons against each other.
Judge Death. He killed everyone on his own world, and has come to Dredd’s universe seeking to do the same. His ultimate goal : to kill every living creature in all worlds.
Yeah, but Thanos has saved the universe as many times as he’s risked it. He was also the instrument used to prevent any more “getting better” amongst the marvel heroes. For that, he is the greatest hero of them all. 
Menocchio, you don’t think Carnage would torture and kill family members? He would. On the way there, he’d kill some people. Once he was done he’d kill some more. When the cops came, he’d kill them. He would torture and kill a kids parents right in front of them, then leave the kid alive and covered in blood for giggles. Carnage is so friggin nuts he’s left messages for heroes in his own blood.
I’m not going to try to say that Cletus Kasady is as creative as the Joker, but he is way crazier and way more evil.
What? And no one’s mentioned the really, really BIG BAD GUY from Preacher?
Ranchoth, Priceguy, I consider that pretty frikkin’ evil. Evil people don’t think they’re evil – everyone thinks they’re doing good.
Good one, Scott.
Hmm, Menocchio makes a fine case for our boy Uxas of Apokolips. Indeed, I’m going to pretend to be convinced so I can make the following joke:
Who is the most evil villain in comics history?
Darkseid Is.
–Cliffy
Everyone who didn’t try to do away with Tintin (he was an annoying brat, all said and done).
Judge Death had a good line in evil. Criminality is bad, only living beings are criminals, therefore destroying all living beings will stop crime forever.
Reggie Mantle…always trying to make time with Ronnie.
I don’t suppose it could be Todd McFarlane or John Byrne?
All of you are wrong. By far, the most pure, unadultered evil in comics is Ambush Bug.
Egghead ruins Henry Pyms life. (I’m not sure how)
Kang manipulates Tony Stark and nearly turns him into a villian.
Kingpin destroys Matt Murdocks life.
To me these villians are the ultimate defiition of evil.
[HIJACK]Actually, Pym had done a good job of ruining his own life before Egghead stepped in to put the icing on his cake: Yellowjacket (as he was known at the time) had suffered the latest in a long series of nervous breakdowns due to his perceived failings as a scientist, husband-provider, and superhero. He had been expulsed from the Avengers due to conduct unbecoming a member, and the Wasp had kicked him out & divorced him after he slapped her around. Pym was homeless and penniless when Egghead framed him for the attempted heist of nuclear weaponry. Pym went to jail, was ridiculed by fellow inmates (some of whom he’d help put behind bars) and was daily delivered gossip magazines that detailed the Wasp’s rebound relationship with Tony Stark. (Pym eventually exonerated himself, of course!) For the full story: Mighty Avengers #s 213 - 230.[/HIJACK]
IMHO, Loki is the most evil villain in comic book history. His crowning achievement (during Walt Simonsen’s run on “Thor”) was to frustrate the good-hearted, virtuous Baldar into commiting (what Baldar thought at least) cold-blooded murder. And for what? “An excellent jest!” Aside from siccing a horde of man-eating trolls on him, Loki injured Baldar in the most profound, soul-searing way imaginable…all for a mere chuckle! That is evil!!
I was going to vote for the Anti-Monitor (destroying every multiverse that ever was), but on second thought it should be Thanos.
Killing an entire universe to impress your girlfriend? Boy, that be whack.
I gotta go with Reggie. I mean, Archie just wants to get his groove on with Betty and Veronica–who wouldn’t?–and Reggie’s a total dickhead about it. I don’t have any Darkseids or Thanoses in my life, but I’ve known a Reggie or two, and hanging’s too good for 'em!
I think that the idea of including Reggie on this list is totally rediculous. Bah, Humbug!
WHooooooooooo
Oh my god, did you hear that? Oh no, it’s the skeletons in my closet! They are reminding me that that Reggie counts under any definition, not just by being a comic book character , but by being able to turn into the costumed villain Evilheart, scourge of Captain Pureheart (Archie) and Superteen (Betty) as well as…not much else, I guess.
Yeah, but they drew Loki as totally Schizo. Sometimes he’s a joker, just going around doing hilarious things and causing mayhem, but without a real evil will behind it. Sometimes they go way the other way and turn him into the JOker. Personally, I like the former version.