If you're looking for somewhere to satisfy every level of skier, you can't go far wrong if you choose the French resort of Courchevel. This is the main resort of the huge Trois Vallees area, which is the largest, inter-linked ski-area in the World.
As well as having what is probably the best beginners' slopes of any resort (these are very extensive, are served by a variety of lifts, including a gondola, and offer superb opportunities for progression to the intermediate level), Courchevel has numerous expert runs. The three marked couloirs, which descend from La Saulire, are a good test for most would-be experts and the area has extensive off-piste possibilities. Add to this the well-developed links to the other Three Valleys' resorts and you have what is probably the most extensive and most varied skiing in the World.
Meribel has the liveliest apres ski in the area and is the best base for skiing the whole of the three valleys. Val Thorens, at 2,300m the highest ski village in Europe, provides snowsure cover throughout the season, with superb on and off-piste skiing, particularly from the top of Cime de Caron. Not to be ignored is the wonderful skiing from Pointe de la Masse, above Les Menuires. The superb lift connections make the once arduous trip across from Courchevel to Val Thorens possible for most intermediates. This can now be done in about an hour allowing for no queueing for lifts. Leave plenty of time for the return journey.
This area is excellent for families and large groups, as all ability levels will find something to satisfy them. School groups can be well catered for but beginners are best taught in Courchevel rather than in Meribel. One of the problems for groups is that there is very little for those who don't want to ski and evening activities are fairly limited (especially for school groups).
La Tania, which lies close to Courchevel 1300, is a cheaper place to stay, yet offers swift access into the Three Valleys' system. Courchevel 1650 also offers a cheaper alternative to staying at 1850, as well as having its own skiing area (this has some excellent runs, especially when there's powder).
The fourth valley (Orelle) is now easily accessible and a new blue run (Lory) accessed from the Funitel de Thorens makes the journey even easier. Beware the final slope of this run (32degrees), though a blue track circumvents this.
If you're staying in Val Thorens and fancy a meal out, I can recommend La Joyeuse Fondue and Le Chaudron Magique, both on the Rue du Soleil.
Two other activities to try are the zip wire from the Fourth Valley and Speed Mountain in Les Menuires - a fast Apine Coaster.