Suburbs like Mesa, Henderson, or Aurora are NOT included for convience. I'll say Colorado Springs, with Las Vegas and Denver close in. I would love to move to this area of the country sometime in my lifetime.
Colorado Springs? WTF? Seriously, Colorado Springs is terrible even if you put politics aside. As for me, it's probably a tie between Las Vegas and Denver.
Why is Colorado Springs terrible? For starters its right next to beautiful mountains and many national parks. I've never been there, so what have you faced when you went there? (or do you live there?)