Which Foe Would Give this Avengers Roster the Most Problems?

[Argonus]

Captain America
Iron Man & Tony's ingenuity
Thor & Asgardian ties
Hulk & Bruce's ingenuity
Hawkeye
Black Widow & ties to SHIELD
.....
.....
.....
Nick Fury (SHIELD)
Maria Hill (SHIELD)
(hahah.. she was hotter than SJ, to me).

Yeah... the movie roster. Which foe would give them the biggest headache, or what areas are they lacking in?

DON'T tie this in to the villain for Avengers 2, at least not for another week or so; you can discuss that villain without saying that's the villain who's referenced in the movie.

The only thing that smacks me in the face directly is that they have no magic-wielders; Mjolnir has magical properties to it, but that's about it.

[Argonus]

I'd love to see a Kang the Conqueror storyline, personally; I don't know what kind of threat he'd be, but having him transport the team into the distant past or future and watching them adapt (Stark and Banner invent electricity! ) would be great.
Having Steve fight alongside the Avengers during a WW II timejump would be sweet, too.

[cblakey1]

Defenders! 'Course Hulk and Hawkeye would have to switch sides.

.. then there's the little problem of Fox probably owning the rights to Silver Surfer.

[Underdog07]

Graviton

[RichBamf]

I'd love to see Ultron.

That way we're 100% guaranteed to get not only the metal monstrosity, but Hank Jan and potentially Vision too...

[Underdog07]

Ohhhhhhh what about Lava Men?

[HalJordanFan]

Ultron for me.

[Peter-Vell]

How about any powerful telepath?

[Bullseye]

I'd love to see Antman and Wasp so Ultron for me.

[samhain81]

I think Super Skrull and the Skrulls would pose a great threat