Replying to CO trip advice

What’s up guys, my girlfriend and I are from New Zealand and are planning a trip to New York in December, during which time we were thinking of doing a week-long trip to do some skiing in Colorado. Just wondering if people have suggestions on where would be best for us to go? We would stay in one place and are choosing between Aspen, Breckenridge, keystone, copper, but open to other options as well. First off, from what i can gather, it is cheapest to fly to Denver and then shuttle to mountain, is this correct? Second, looking for suggestions on which are easiest/most affordable to get to from Denver, as well as where is best for not ridiculously expensive accomodation in the village, and also is snow alright in all of these places aiming for mid December? Will be first ever time skiing over there so please excuse the lack of knowledge. Any advice appreciated!