Iron Man 2 is not on part with the first movie, not even close ,if anything this is the worst movie of the MCU as yet. The main reason for the decrease in quality from the Iron Man, is that Iron Man 2 is by default a filler,though quit an expensive one (it had a budget of 200 million, 60 million more than the first movie), but filler none the less which exist only to introduce S.H.I.E.L.D. and Black Widow in to the MCU and set the stage for the Avengers.

Not that I am complaining for any of this things (:p), what can I say I am only human. So what is good with it?

First the new actor who plays Rhodey Rhodes is really good and I buy why he and Tony are best friends, Gwyneth Paltrow's Pepper Potts is decent on her role, but the person who steal the show are Samuel L. Jackson's Nick Fury(one of the best casting ever) and Scarlett Johansson's Black Widow, the role that made her in to the A-list actress she is today. For real why anyone in six years after this flick hasn't made a movie with her in the lead role?

Second the action scenes are well executed and the CGI are great and don't disappoint either.

Now the main drawbacks from the film: One the villain is just there in order for Iron Man to have someone to fight. Two the movie's plot is slow and though it is only two hours and five minutes long it feels much longer. Third and final is the man himself (Not Stan Lee) Tony , whose character doesn't change from the whole situation, to be honest after the first Iron Man ,his character will remain mostly the same up to Civil War eight years and five movies later.

In the end Iron Man 2 is an enjoyable movie with good action and a mostly functional plot. An the fact that is the worst for what the Marvel Studio has gave us or among the worst if you include Thor and Thor the Dark World.,which aren't also bad, just not the best, is a sign that this one of the best Franchices in history.