I agree, I actually lived down the street off 18th and Arapahoe, but when I moved and had to come back to pick up my car I spent the night at the Renaissance. Great hotel (there's not much of a view no matter where your room is though) with a hidden gem sushi place across the street.

The only other Marriott property I recommend downtown is the Speinghill of Auroria. Beats the Marriott and CY hands down, costs a little less than Renaissance normally, and great location to get to bars.