Pikes via Barr Trail is a must. Its best if you make it an overnight trip and stay in Barr Camp. It is a wonderful place. Most of the trail is below treeline but has nice view every once in a while. Once above the a-frame its wide open. View are impressive because there is a huge vertical relief over Colorado Springs (elev. 6000ft+-) and other hills in the area. The alpine terrain is barren but the cirque (off to the left on one of the switchbacks on the trail, there is a sign), bottomless pit (to the right of the trail, can be seen from above if you go on the pikes road or as a detour from barr trail) and specially the couloirs off Devil's Playground are a must see (on the road up to pikes). Beware of wind, the terrain is very exposed up there, nowehere to hide, and its almost always windy (20-40mph is the norm)
Besides that there are lots of other novice hikes in Colorado (like the ones mentioned) that have great views and terrain. Its always best to team up with a local. It will reduce the stress and maximize safety and enjoyment. But even alone there is plenty of good beta available and most trails are well used. Go prepared and you will have a lot of fun.