Twilight- Twi, Twili, Sparklers
Fluttershy- Flutterbutter, Flutters
Rainbow Dash- Dashie, Rainy
Applejack- AJ, Appersauce
Rarity- Rare Soft, Disparity (when she's being overly dramatic sad)
Pinkie Pie- Pinks, Pinkster
Luna- Lulu, Woona
Celestia- Sun Butt, Princess of Trolls