Pretty much what everyone said.
Breck if you want to wait in lines for mediocre skiing (in bounds) and an amazing park. Parking is a bitch too.
Key for easy access free parking, a great park, and not much else.
Copper for pretty easy parking (really easy if you know what you're doing) and fun terrain. Park is alright but I'm glad it's not their biggest attraction.
Obviously the real discussion here is Super Pass vs Epic/Locals Pass. I like the Super Pass Plus because after two years of skiing with the Colorado Pass (now Locals Pass) I realized it is rarely worth it to ski Breck or Key due to crowds and lack of terrain. A Bay, Vail, and Beaver Creek are all sick for fun terrain but the latter two are too far away from Denver to ski every weekend. Between Copper and WP I get everything I could ask for and more. Both areas have great all mountain terrain. Being from VT I appreciate good woods and Mary Jane has some of the best woods I've ever skied in bounds any where, period. Overall you can't go wrong with your decision if you're in Grand County or Summit County. Western/Southwestern CO has incredible terrain if you ever get a chance to visit or live there as well.
