1 Adrian Toomes / Vulture (Spider-Man: Homecoming)
He takes the top spot because he's a father struggling to make ends meet after his cleanup crew gets shafted by damage control. - NuMetalManiak
2 Thanos (Avengers: Infinity War)
Thanos is a fictional supervillain appearing in American comic books published by Marvel Comics. The character was created by Jim Starlin and Mike Friedrich. The character first appeared in Iron Man #55 and has been portrayed by actors Damion Poitier and Josh Brolin in the Marvel Cinematic Universe.
Well, obviously. He's got his motives and never stops sharing what they are and how he plans to do it. - NuMetalManiak
3 Justin Hammer (Iron Man 2)
In many ways, the business rival of Stark really just wanted to be better than Stark, and while a behind-the-scenes villain as opposed to Whiplash, he was actually the more fun villain of the 2nd Iron Man movie. - NuMetalManiak
4 Obadiah Stane / Iron Monger (Iron Man)
5 Aldrich Killian (Iron Man 3)
6 Loki (Avengers)
Loki Laufeyson, or Loki Odinson, is a fictional character appearing in the American comic books published by Marvel Comics. He is the adoptive brother and archenemy of Thor, and is known as the "God of Mischief". In the Marvel Cinematic Universe, the character has been portrayed by Tom Hiddleston.
7 Ultron (Avengers: Age of Ultron)
Ultron is a fictional supervillain appearing in American comic books published by Marvel Comics. He is most recognized as a foe of the Avengers, and has a quasi-familial relationship with several of their members, especially his creator Hank Pym.
8 Hela (Thor: Ragnarok)
Being imprisoned by her father because of her potential ambitions to rule and to create death definitely does a number on Hela. - NuMetalManiak
9 Ronan (Guardians of the Galaxy)
Ronan the Accuser is a fictional character appearing in American comic books published by Marvel Comics.
10 Quentin Beck / Mysterio (Spider-Man: Far from Home)