Used to live there a few years ago. If you've never been, it's worth doing a few of the tourist-y things like wandering through the beautiful rock formations of Garden of the Gods, checking out the grounds of the Broadmoor Hotel complex on a nice day, hiking through Palmer Park in the middle of town, or taking a drive north of town and exploring Castlewood Canyon State Park (one of my favorite spots). If the weather is good and the trails are open, challenge yourself with an early morning hike to the summit of Pikes Peak (tops out at 14,100 feet, I believe). Otherwise, take the train up. If you're looking for a decent meal, try the Blue Star, or for something a littel fancier the Summit at the Broadmoor. Or just go for a good pub meal at Phantom Canyon downtown. Surprisingly, I never managed to find a really good Mexican restaurant there, but am sure they exist. There used to be one gay bar and beside it was some kind of a sauna but I didn't frequent them so can't really comment on them.
In short, COS has some great natural features that are worth checking out. But as a city, sometimes it's best to just... drive north to Denver.