There's no "best move" for the contests. Each move has its respective advantages and disadvantages.
Example: Bide only gives 1 appeal, no jam, but it has the added effect of avoiding being startled by other Pokemon, which can be useful.
Bind, however, gives 3 appeal, no jam, but it has the downside of temporarily stopping the crowd from being excited.
All moves have added side effects that you need to account for. So there's no "best move", since appeal isn't always everything. There are also so many moves to go through that it's too hard to say which one is the "best" for gaining appeal. I suggest you pick a Pokemon, look through its Gen III moveset on Bulbapedia and make a moveset from that. Your choices are limited anyway, since you can't reuse TMs in Gen III.
(By the way, if you're doing contests for any other reason than the fact that you enjoy them, don't. It's a waste of time otherwise.)
