I like it, but IMO it's one of his lesser films.
I think Batman Begins, The Prestige, and TDKR have messy third acts (actually TDKR is sort of messy in general), but I don't agree about Inception.
I've actually (gasp, shock) never seen Memento.
It's definitely not his strong suit. Although Inception's action was better than Batman's, for some reason. That weightless hallway fight was one of the coolest fight scenes since The Matrix. But yea, Batman fight scenes are a mess. The car chases are okay, but he can't shoot fight scenes (at least not with Batman).
Agree to a point. I felt nothing at the Waynes' murder in Batman Begins, or Rachel's death in TDK. I felt TDKR had more feeling, personally, and I thought Inception had some moving scenes (old Cobb and Mal walking through their dream city

).
Not bad but probably the least of his movies.