What is the best superhero movie?

[PlasmaTwa2]

I got into a little debate at work last night with my coworker over which superhero movie is the greatest. He says it is The Dark Knight and I say it is the original Superman. We agreed that they are both amazing, but it got surprisingly bitter when we tried arguing which one was the best. He argued TDK is the greatest because it transcendes the superhero genre and is a great film any way you look at it; as a thriller, drama, action, etc. He also said that it's got the greatest performance by Heath Ledger, a point I disagreed with on behalf of Christopher Reeve. For my part, I think Superman is the best because it was the first movie to ever get the superhero genre right, not to mention get a difficult character like Superman done so iconically. I also find Superman to be more emotionally compelling than The Dark Knight due to things like the music and the character of Superman himself compared to Batman.

So what does the fabled cast of FreeOnes think is the best superhero movie? The original Batman? Spider-Man 2? Howard the Duck?