So The Incredible Hulk movie was the exact, perfect movie made for that character.  Now, Bruce Banner is no Tony Stark.  He's not carefree, he's haunted by a killer inside him.  So the tone of the story isn't going to like Iron Man.  How do you make an interesting movie about a Hulk, when your main character doesn't want to become the Hulk?  But they pulled it off.

Here's all the major points of why the movie worked:

They brilliantly kickoff the movie with a montage which tells about 30 minutes of story in 3. 

Cast.  Edward Norton is great.  Liv Tyler is great.  William Hurt is great.  Tim Roth is great.  Everyone works.

The Marvel Universe. These are no longer stand alone movies. The events in Iron Man are taken as fact in this movie.  It looks like they are laying the groundwork for Captain America and The Avengers movie.   

The special effects.  Yes, the CG looks goofy in the trailers - but in context of the movie it's totally fine.

The Hulk Smashing.  Perfect!  I've been saying it all along since Ang Lee's Hulk, "They should just have Hulk and Abomination pounding on each other."

I really like X-Men 2, Iron Man and Batman Begins.  And, I really like The Incredible Hulk.