Warning: Possible Spoilers
TDKR opens about 8 years after "The Dark Knight" left off. Gotham City is honoring Harvey Dent with Harvey Dent Day, and Bruce Wayne is a recluse, taking the blame for what Harvey did (after he became Two Face) and for killing Harvey. the whole city thinks Batman is the bad guy. This part made absolutely NO sense, and started TDKR on a negative note. When an evil terrorist terrorist named Bane arrives and threatens to destroy Gotham City, Bruce decides to return as Batman.
For starters, Batman spends almost half the movie, which was 2:40 long, recovering/rehabbing: first, when he returns to Gotham, and also after his first battle with Bane. Most of the rest is pure destruction. There is also a bed scene which is completely unnecessary to the story (no nudity).
The two bright spots are Anne Hathaway, who steals the show as Selina Kyle/Catwoman, and Joseph Gordon-Levitt, who is excellent as Detective John Blake, one of the few who believes in Batman.
There is a nice plot twist toward the end, but it is too late to save this morbid story. I really hope they meant it when they said this is the end of The Dark Knight story.
2 words: DISAPPOINTING and DEPRESSING. Very over-rated. Save your money.