Thats why you have to come during football season. Head up to the mountains and ski Keystone on Friday. Head up to Boulder for a CU game on Saturady morning. Head down to the Pepsi center to watch the Avs, or Nuggies play Saturday night, then watch Cutler and the Donkeys whoop someones ass on Sunday. Throw in some Steak dinner at Elway's and some microbrews at Wynkoop, and that my friends is how you enjoy the weekend in Colorado.
Even LoDo downtown is kinda dead in the summer. But Denver really is about the entire area surrounding it. If you were stuck in a Mariott somewhere around 16th St, then yeah, I can see how you would not be so impressed.
Next time consult the Pitman Travel Agency. I got the hookups!