I never thought DW could get much better than "Blink", "Turn Left" or "Girl In The Fireplace" (the first tear-jerker episode) and certainly not with Matt Smith who, although one of the best Doctors, plays heavily on his silly side ('bowties are cool', 'fezzes are cool', 'glasses are cool').
Fortunately, though this episode features only the three main characters, apart from the Handbots, the Doctor is almost irrelevant as the story turns around Rory and Amy. When Steven Moffat first introduced Amy Pond he told us she would be the strongest female companion the Doctor had ever had and he was not lying: she is a million light years away from the early ones who would scream at the sight of a bug-eyed monster.
Amy is just magnificent, especially as her older self, and leaves us with the hope of character development in future episodes.
And if you haven't seen it yet get out a few tissues as the ending may bring you to tears. Definitely one of the 'must-haves' in your video collection.