We've skied Monarch as a large group for the past 3 Decembers and experienced powder days each year. No lift lines, excellent grooming (if it doesn't get covered by a heavy snowfall)and a great staff. Excellent ski school for the kids and diverse runs for them to challenge their abilities. Lodging is sparse and the weather is always cold but the trade-off for snow is worth it.
The only downside is the lack of high-speed lifts but the absence of lines and skiers is worth the trade off. Top of the list for overall value (ticket price, snow quality).