Rocky Mountain National Park is a great place to visit. If you want to do some fishing with a good chance to see some bear check out the Red Feather Lakes up North and about a gazillion other reasons to go to the state.
I know ever has stated the snow and the amazing winter wonderland in the mountains. But how about being able to ride 2 feet of fresh powder in the morning and coming back to play 18 holes of golf in the afternoon with 57 degree weather in the middle of December. Can't beat that IMHO!!