I found the Avengers to be overblown and over-the-top. It wass fun to watch, sure, and you can't beat Tony Stark/C.A wittiness, but I prefer semi-realistic superhero movies such as TDK.
The problem with the Avengers, for me, was that the destruction and heroics eventually got to such a level that I felt overwhelmed by the relentless assault on my senses. The number of explosions made all of Micheal Bay's films look like The Shawshank Redemption.
I'm not saying it was a bad film, because it wasn't bad by any measure. "It's not you, it's me". That is the issue. I don't personally enjoy films like that anyway, so for the Avengers to be an enjoyable experience is quite a feat in itself - proving it is a great film. Just not a great film to me.
Nolan's Batman films have been amazing, incredible yet still grounded in reality - and an immensely enjoyable, riveting and sometimes shocking experience. That is the reason why, whether Rises is as good as TDK, it will be better than the Avengers for me.