In reply to DaveHK:
Serre chevelier is a good bet, it's near briancon on on the boarder of France and Italy.
Look into alpe d'huez, good pistes, very accessible off piste which is often untouched. Although if your going off piste please don't thnk because you can see a lift you're safe.
If you don't have all the gear and know how to use it I can't stress enough not going off piste. For someone only 20 I know too many people who thought they knew better, some were lucky, some weren't.
Although Tinges val Thorens, val disere are all fantastic lift systems they're often too crowded.
But if you really want to push yourself then Chamonix all the way!