Which characters are the hardest to put down?

Magneto, Doom

I'm surprised the Hulk has been mentioned yet. Especially the Green Scar incarnation.

Thor has some pretty crazy damage soak as well. Except when he faces the Prince of Power Cho that is.

Originally posted by KuRuPT Thanosi
Thanos

Originally posted by janus77
not really, any old sonics/electrics capable street leveller could do it, imo.
plus those of sufficient strength.

Stardust/Surfer.

False on so many levels.

Juggernaut.

Better durability than most. And even if you hurt him, his regen is great as well.

The Mask, I win!

h1a8

I actually burst into laughter here

Morgan le Fay
Stardust
Sersi
Juggernaut
Iceman
Martians
Emma Frost

Conceptually, Dust should be up there too. Low showings though =[

Originally posted by Konton

Conceptually, Dust should be up there too. Low showings though =[

Mercury, too. Other than electric shock, not much should phase her.

Unfortunately a lot of characters can generate electricity ;p

Originally posted by Konton
Unfortunately a lot of characters can generate electricity ;p

I submit to you that the majority of them cannot.

Swamp Thing, unless he counts as a cosmic

Drax.

plastic man

Originally posted by 753
plastic man

this

Originally posted by Konton
Emma Frost

??

Originally posted by Prep-Man
No cosmics, BTW.

Pre-Crisis Shaggy Man.

So I assume anyone under Skyfather is fair game?

If so, then the Asgardian Destroyer is the answer here; its tougher to defeat than classic Juggs or Thanos...

Ah, the Winslow from Buck Godot, Zap Gun for Hire is insanely hard to do anything to (as far as anyone can tell, impossible. And "anyone" includes some higher dimension beings of tremendous power).

Oh, and Mr. Immortal. Well, you can knock him out easily, just not kill him.

Originally posted by Warlord
??

Unless you're capable of matter manipulation or happen to have a very dense bullet on hand (diamond/vibranium/adamantium) with the ability to sharp-shoot microscopic flaws, you can't really beat Emma. She's never been KOd in diamond form, doesn't sleep, doesn't eat, doesn't drink, doesn't breathe, doesn't break.