I feel like the best thing about Doctor Doom is his unmatched versatility as a character. He's the Fantastic Four's greatest nemesis, and has the biggest rivalry in all of comics with Reed Richards. Yet, he doesn't have to be an FF villain. Doom has tangled with many heroes throughout the MU, in very different stories, while the FF were nowhere in sight. Even better, none of this diminishes his role as the FF's greatest enemy or Reed's fiercest rival.

Seriously, you can make an excellent story out of...
  • Doom vs. Avengers
  • Doom vs. Strange
  • Doom vs. Thor
  • Doom vs. Black Panther
  • Doom vs. Iron Man
  • Doom vs. X-Men
  • Doom vs. Hulk
  • Doom vs. Spider-Man
  • Doom vs. Captain America
  • Doom vs. Everyone

And so on. He's just got that kind of style and charisma to him that makes it work no matter what story he's in. I think the versatility is due to the facets of his personality and style. He can be a criminal mastermind, a powerful sorcerer, a mad scientist, a political figure, a greater scope villain, an uneasy ally, and so on, and it's believable because all elements are well-developed and explored.

Are there any other villains who have this level of versatility to them as characters?

That's what I wonder since many villains fit a specific niche, but not Doom. What do you think?