I have two that I love. Both were for the same story.

"The perfect conclusion. It was an amazing, adventurous story, and I enjoyed reading every chapter. Your Ba Sing Se was so well described, so lived-in, and as well-crafted as Tolkein's or Pratchett's worlds. I think every fan of the show relished the chance to spend more time in the Avatar universe."

"I really enjoyed this story. It's hard to even think of this as fan fiction since it only really borrows one corner of the setting; the characters and the plot are all your own, and they were great. The characters had depth and pathos, and their interactions and dialog made for some wonderful, humorous, and heartbreaking moments. They struggled with racism, classism, and sexuality, and you approached all of those topics with a class and dignity that didn't seem at all self-indulgent on your part. I've consumed an almost embarrassing amount of fan content since this series ended a year and a half ago, and I can't possibly stress how rare that last point is."