Tignes is sic! It is huge, high and varied. If you want glades best go mid season but for nearly all year round riding in the Alpes it is very hard to beat. Val D is just over the hill with a natural terrain park. The lifts are mostly fast and there are usually plenty of routes to where you wanna go. To ride it all you would need a season plus.
Its not a cheap lift pass but worth it, there are two main towns to Tignes both are good for the crack but stay in between them or a little ways away if want a quite night in as it can get a little loud late in to the morning. Tignes is all that, and a bag of popcorn!