This first one will always stand out in my head as it is the poor horses actual name...he was a little Appy at my stable back in the late 80's early 90's and his registered name is...
Panty Raider (yes look him up on ABP, you'll find him)
Some others I didn't like were
Oodles of Noodles (huh, how is THAT a horse name?)
Courvoisier (only because announcers had issues pronouncing it)
And Rabbit Stompin Fool (always made me think of a horse crushing cute little bunnies to death)