I would take any, but I'm kind of partial to Western Slope. I lived in Montrose for over 6 years, and it's the real Colorado experience. A bit harder to get to but well worth the drive.
• San Juan Mountain range — some of the most beautiful rugged mountains you will ever see. All the Coors mountain shots are filmed here.
San Juan Mountains - Wikipedia, the free encyclopedia
• You have 10,000" flat-top mountains, you can drive on with the Grand Mesa in Grand Junction. It has great fishing and tons of lakes. The Colorado National Monument is also right there.
Touring Colorado - The Grand Mesa National Scenic and Historic Byway
• Some of the best wineries and fruit in state at Palisade.
Palisade Chamber of Commerce - Welcome
• Narrow gage STEAM engine trips in Durango.
Family Discount on Selected Days! | Durango & Silverton Narrow Gauge Railroad Train
• Beautiful box canyon in Ouray CO (called little Switzerland) with a natural hot springs pool.
Ouray Colorado :: Home
• Million Dollar Highway - this is perhaps the most beautiful and horrifying adventures you can experienced in a car. If you are attracted to stunning scenery with sheer cliffs and NO GUARD RAILS, this is the road for you!
• Telluride - some of the coolest skiing, golf and concerts in all of Colorado. Very pretty but a bit pricey $$$, Oprah and Cruise both have homes here.
Telluride Ski Resort | Mountain Ski & Summer Resort Events & Activities
Plus the bonus of driving 5-6 hours (ALL mountain driving) just to get there from Denver or Colorado Springs.