I spent 2 weeks in Val Thorens over christmas and new year, it was utterly amazing. VT is a perfect base to expore the whole 3 valleys, nto to mention the expansive terrain you have on your doorstep. Orelle is excellent and well worth the trek to get to.
People give VT a hard time about the weather, but in two weeks there was only 1 day where the wind took control of the mountain and the lifts where shut (luckily this was boxing day, so actually work out well).
Nightlife here is also excllent, energetic Apres Ski, great clubs and really good variety of places to eat.
VT is a must for anyone looking for great snow conditions and a lively down to earth town.