What is the worst dimension in the Marvel Universe?
Hands-down, the so-called ‘Zombie-verse'!! Marvel totally jumped the shark when they drank the kool-aid and caved to the worst media concept of the 2000's by creating this alternate Earth!! I stopped being a regular reader when they decided to add to the glut of zombies in every media. Don't get me wrong,I still read the occassional great story that catches my interest, such as the origin of Marvel's "American Kaiju"! As far as I'm concerned, as of the Summer of 2013, zombies are not just stupid, they're DEAD.......because the KAIJUS HAVE RETURNED!! This was only reinforced in 2014 with the return of the King of all kaiju GODZILLA HIMSELF!!!!
End of rant.
I would say earth 11080, which is the earth featured in "Punisher vs The Marvel Universe." A chemical weapon is released into the water supply of New York and former superheroes begin reverting back to tribal ways, and also they're cannibals. The heroes end up eating almost all humans and start fighting eachother. It's a pretty grim world. The marvel zombies universe comes in a close second.