My absolute favorite review is from StoryJunkie, the first on From the Looking Glass, it was so random and entertaining and completely unhelpful yet glowing that I loved it.
My second favorite review really came in two parts, the first was telling me what I had done wrong and why the second congratulating me on how much I had improved when I had fixed it. Of course the reviewer's spelling is atrocious and they're hard to read again, but meh...
Lots of other good reviews too, especially on my first Naruto fic (a one shot Chouji Sakura) mostly because no one expected or really wanted the pairing but liked the story nonetheless.