Places and things to do around Colorado Springs and Denver?

Wow, where to start... there's a TON to do around Colorado Springs and Denver.
Here are some highlights.

Garden of the Gods is a must-stop if you are in the Springs. You'll want your camera at the river. Colorado City is a fun place to stroll. Some good restaurants and shopping. Manitou Springs is also an interesting place. The Cliff House at Pikes Peak is a good place to stay, but not necessarily if you are on a budget.

If you like zoos, Cheyenne Mountain Zoo is probably one of the best zoos in the country (according to me).  :-) Located on a hill, the layout is unique and if you like giraffes they have the top zoo breeding program in the country.

In Denver on a budget, you can stroll Larimer Square and 16th Street Mall, but that's just city stuff. You could drive or hop on the light rail and spend a day in Golden (Colorado). There are a number of hikes in the area and great breweries. 

The remodeled Denver Union Station is a must-see. It's an amazing train station if you're into such things.

That's all for now. I could go on and on. These are the two largest cities in Colorado, so this question is sort of difficult to answer!!!