File photo | The Associated Press “The Avengers” could defeat three of the AFC West teams without even breaking a sweat.

GRADE: A

Joss Whedon’s “The Avengers” perfectly hits the superhero middle ground between the stiflingly serious (like Christopher Nolan’s Batman trilogy) and the stupidly silly (hello, “Green Lantern”).

This all-star Marvel mash-up delivers sly humor (in the form of Robert Downey Jr.’s Iron Man), grandiosity (from Chris Hemsworth’s Thor), true-blue heroism (in Chris Evans’ Captain America), sexy toughness (thank you, Scarlett Johanssen as Black Widow), cool detachment (courtesy of Samuel L. Jackson’s Nick Fury and Jeremy Renner’s Hawkeye) and tragic irony (brought by a pre-Hulk Mark Ruffalo, the movie’s MVP).

Battling both Thor’s demigod brother Loki (Tom Hiddleston) and their super-sized egos, the Avengers come together to form a fierce fighting team under Whedon — who balances visual thrills with witty banter, gives supporting characters strong moments, and has a good ear for what makes nerds ecstatic. Extras include deleted scenes and a short film, “Item 47” (on the two-disc combo), and a digital download of the soundtrack (on the four-disc combo package).