Pinkie VS Fluttershy. The comedy relief, or the cuteness. Go.
I gotta go with Pinkie on this one. She steals the attention whenever she is on screen, because you never know what fourth wall, law of physics or other law of nature she will break with her teleportation powers, ability to morph into mirrors and other objects, etc. She's also the absolute cure for sadness, as watching her antics is simply funny. Fluttershy may be cute, but honestly, all the ponies are cute and have their own individual cute moments, so her over-the-top cuteness doesn't beat out Pinkie for me.
Edited by ~Chaotic Discord~, 06 June 2012 - 11:20 AM.