Not as funny as Troy in 15 minutes, but still good. Harry Potter and the Prisoner of Azkaban in 15 Minutes by Cleolinda. Warning, contains spoilers and adult language.
Excerpt:
The Shrieking Shack
RON: Help! Help!
HARRY: We’re coming, Ron!
RON: Don’t help! Don’t help! It’s a trap!
HARRY: *eye roll*
BIG BLACK DOG: *turns into Sirius Black*
HERMIONE: If you want to kill Harry, you’ll have to kill us first!
HP FANS: OMGWTF THAT WAS RON’S LINE! YOU CHANGED THINGS FROM THE BOOK!
LOTR FANS: What are you, new?