Villains from the first 50 issues of The Fantastic Four comic:
The Mole Man
The Skrulls from Outer Space
Miracle Man
Sub-Mariner
Dr. Doom
Kurrgo, Master of Planet X
Puppet Master
The Impossible Man
The Red Ghost
The Mad Thinker
Dr. Doom
Super Skrull
Rama Tut
Molecule Man
Hate-Monger
Mole Man
Infant Terrible
Diablo
Invincible Man
Attuma
Gregory Gideon
The Frightful Four
Medusa and Gorgon
The Inhumans
Galactus
Thanks to Velvis for this list.