In France, Avoriaz and Tignes take some of the top snowboarding spots, Tignes ranks especially well with 300km of piste, 2 halfpipes and 2 terrain parks as well as some amazing off-piste.
Mayrhofen in Austria also has a good snow park as does Sauze d'Oulx in Italy. In Verbier, Switzerland and St Anton, Austria, you'll get the added benefit of some excellent freeeride terrain.
The best resorts for beginner boarders are Arinsal in Andorra, Risoul in France and Saas Fee in Switzerland.