USA Sloan's Lake Park, Denver, CO

Sloan's Lake Park offers a very nice view of the Denver skyline from the west. It's great for pre-sunrise shots and sunset shots. The Denver skyline isn't exactly spectacular, so having another interesting element in your composition, such as the lake, really helps.

Definitely bring a telephoto lens (e.g., a 70-200mm) if you have one. You're pretty far removed from the skyline, so if you want the skyline to take up very much of the frame you'll need a longer lens. The standard advice regarding tripods and graduated filters applies if you're going to be shooting sunrises/sunsets.

Google will get you to the general area. The southwest corner is my favorite spot because it has a bridge that can act as another compositional element (shown in the second picture). It's easiest to park on the west side of Sheridan in one of the massive parking lots and then cross the street, but there is some parking specifically for the park in the area as well.