You've listed some places I would like to see too! But they keep closing Mount Blue Sky (Mount Evans with it's already short open season!)) and I've also found that many of the more obscure or large general places like Berthoud Pass don't have enamel pins to collect.

Mesa Verde was closed for fires when we tried to visit and with the horrible number of major accidents and closures on I-70 we try not to use it much anymore. I do have a list of lesser known places like Bishop Castle, Paint Mines, and Wheeler Geologic Area on my Colorado bucket list.
Which places in Colorado have you been to?