My personal favorite is
Solitude Mountain Resort. It definitely isn't the biggest resort here, but is by far the least crowded. There is no such thing as a lift line at Solitude. [img]/images/graemlins/cool.gif[/img]
If terrain parks and superpipes are your thing then
Brighton Ski Resort is the spot. This resort is usually rated in the top 3 by all the snowboard magazines. Believe it or not, the snowboarders far out number the skiers at Brighton.
If you're after double-blacks and cliff drops then
Snowbird is where you want to be. Snowbird is definitely the most crowded, but they also have a high speed tram and are able to move a lot of people up the mountain quickly.
All of the places I mentioned above are near Salt Lake City, which is about a 6.5 hour drive from Vegas (in good weather). Although they all receive an average anual snowfall of over 500", Snowbird always has the longest season and plans to close on May 29th this year (last season they were open until July 4th!).
The closest Utah resort to Vegas is
Brian Head. This resort is about 1.5-2 hours from Vegas and has the shortest season in the state due to it's Southern location and lower altitude.