I don't see where people get the "overrated" thing from... I guess we all have our own opinions and all.
But to me, this really was the best superhero movie ever made. It beat out the original Superman in my mind. It probably helps that I have been a Batman fan since I was a very young child... it might help that my Mother died when I was a kid and the story of Batman was therapy to my damaged psyche...
The stars seemed to align for me with this movie, Batman was played perfectly, they actually got the Joker and Two Face right.. well, exactly the way I like them to be. Gordon was exactly as I would want him, as excellent as when he was written by Frank Miller in Year One. The story was captivating, shocking, and intense. The music was rousing, sad and tense at times. I couldn't have asked for a better vision of Batman or his universe.
And I was a HUGE fan of the Burton Batman, I never thought it would be improved upon. Begins broke it's hold on me, and TDK forever wrested it's dominant grip on my mind.
I don't know if Watchmen might be better, when I finally see it... But with Batman being so personal to me, I doubt it will take the top seat away from TDK. At least to me.