Batman Begins is too much of a diamond in the rough. I feel it gets overrated because it followed two very horrible reiterations of the character, so it took a wildly different approach and gets near universial praise for it. Though the end result is nothing too spectacular. Batman Begins is like a great pitch meeting, a TON of good ideas are thrown out, but the end product ends up being an inconsistent mess of jumbled plot ideas.
Batman Begins in very much a different film in it's first act than it is in it's last. Due to the fact the movie lacks truly engaging villains, it attempts to make up for this by including an absolutely dreadful show down on a microwave emitting monorail. It totally abandons it's tone of realism for a cliche' comic book ending, complete with exposition so bad it would make infomercial writers groan. Combine that with a script that is marred by awful dialogue that doesn't even resemble the way people actually talk, and what you have left is one big mess.
Granted the film's saving grace is the admireale acting jobs by Liam Nesson, Morgan Freeman, Christian Bale and Cillian Murphy; and the direction by Christopher Nolan (fights scenes notwithstanding). Unfortunately none of their characters are written well enough for this movie to really stand out for me. The movie is about as subtle and nuanced as a sledgehammer.
Iron Man on the other hand might seem like your run of the mill blockbuster, but packs enough in to actually make it a very smart, comic "accurate" and savvy film. The character of Tony Stark is developed with a lot less dialogue, and the characters of Yinsen and Stane are used to incredible effect. The villain, ironically, is very interesting and compelling (considering all of the Iron Man villains typically suck wind). Also Jon Faveuru had a more daunting task: make a GOOD IRON MAN MOVIE.
Batman's story is compelling as it is. Even marred with bad dialogue it's so engrained in the public conscious that people already know it's greatness. It's had years upon years or revision to make it thoroughly convincing and compelling. Iron Man, in the eyes of the public, is a C-lister at best. In the comic world, Thor, Captain America (sans it's main character), all the X-Men titles, 6 titles featuring Wolverine, Spider-Man(s), Hulk(s) and even Punisher tend to outsell him...and that's only in his own company. He's not that popular.
This is due, in large part, to the fact that Iron Man is seriously not all that interesting. For years his only story that he is noted for is "Demon in a bottle", and perhaps the "Armor Wars I and II". He typically has a craptastic rogues gallery, all of which has currently died off (not kidding). The fact that any movie writer could look at this character and do a film that amazing, and do something that embodied the Marvel spirit that well just floors me.