Iron Man 2 is just tolerable. I have just rewatched it recently but I don't hate it.

Robert Downey Jr is the perfect Tony Stark but the plot is a bit too cluttered with Tony's problems and also his past.

But it has great moments with the racetrack sequence, the fight between Rhodey and Iron Man in his house, Black Widow showing her fighting skills and also the chemistry between Rhodey and Stark during the finale.

It's better than people give it credit for but it does have it's problems.