In reply to raliadsa skcalbwah:
Valgrisenche is a beautiful, quiet valley, with good climbing and nice walks up to huts. Otherwise, Champoluc/Val d'ayas is lovely; gressoney and cogne have been mentioned and also good. (Alagna is a long drive and not in Valle d'Aosta)
I'm not sure when you are going, but if you are there whilst the lifts are still open, that might be worth factoring in to your choice as it greatly increases your walking options.