I was just scrolling through the Worst nickname you ever gave to a Pokemon, and thought why not make a counterpart thread?
The best (imo) that I have would be Flufflet my Braviary(Made more sense when he was a Rufflet. That's what I always called them. XD), and Midbus my Emboar(I had to name him that. <3)
That's all I can think of at the top of my head.
-Edit- Oh, sorry. That other thread was stupidest nickname, not worst nickname. ^^;