Relative power/threat level of Avengers

[pr0xyt0xin]

So, I was watching an episode of Avengers: Earth's Mightiest Heroes where they were basically comparing the "threat level" of various avengers.

Something like this:

Hulk: Extreme
Iron Man: High
Thor: High
Captain America: Medium
Hawkeye: Low

So I am curious. Where would others be ranked? I'd rather get your all opinion than make it up myself. Any current or former Avengers you can think of...