A summer Rocky Mountain getaway...we did this for our 5th and 10th anniversary (and honeymoon!
Estes Park is wonderful, at the base of Rocky Mountain National Park and convienent for day tripping to Grand Lake, Boulder, etc. Easy to fly in to Denver. Make sure to book one of the cabin-motels, not a chain like Holiday Inn.
We LOVE it!
Good luck and have fun wherever you go...