The Avengers is a fun film to watch, it kept my attention throughout and had some genuinely funny moments in addition to the drama.
The critical roles given to Black Widow  and Hawkeye were well thought out, and consistently felt natural in the context of the story. In particular this meant that the powerhouses of Captain America, Thor, and Iron Man did not overwhelm the film.
Visually spectacular, especially as I was fortunate enough to see it in 2D, this is a strong addition to the Marvel canon. A definite possibility for picking up on blu-ray later, by which time it may be safe to do a longer review with a synopsis .
 As a side note seeing Black Widow keep up without powers was a nice piece of subverting the usual gender roles in this sort of film. I’m not sure if The Avengers passes the Bechdel Test though.