I prefer Single Battles, don't know why. I'm not too fond of Double/Triple/Rotation battles.
Doubles were always fun for me! Singles get boring quickly, Triples are okay, Rotations are a bit difficult since the opponent can switch their Pokemon when you don't want them to.
Double always! Like when your fast pokemon use fly and then your other use surf great combo!
I am grass/water and dragon trainer
I've always preferred single battles, but double and rotation battles are ok. I'm not really fond of triple battles.
I don't use uber Pokemon , I don't calculate stat values, I don't use cheating devices, I don't breed my way to perfection, and I don't care about natures. I catch my Pokemon the way they are, and treat them like individuals instead of brainless drones. If you use this philosophy, copy & paste this into your signature. (Started by Tyranitar)
Single is the major point on battles. Any other variation of battle is just for casual amusement.