Even though I prefer Iron Man as a hero; I think if he and Batman got into a fight, Batman would win.
Think about it: Batman usually goes prepared for a fight, because usually he goes and finds out what he's up against. Iron Man doesn't find out until the last minute.
Although, I think it'd take a lot of work to make a showdown between the two happen, seeing as how they were both created by different companies and also their movies are currently being produced by different companies as well.
The thing is though, among comic book fans, Iron Man has a reputation as being a bit of a boring hero. I don't really know why this is though, because in the comic books he goes through a lot of different social issues like alcoholism, homelessness, etc. over the course of the many, many years he's been around.
However, there's no denying that Robert Downey Jr. does produce a lot of personality for the character on-screen.
