My thought process: I'm new to Denver, don't have a car, don't know what trails are good or where they are, but I want to get out there and do a nice hike with some beautiful scenery (w/ a bit of cardio). Also, it'd be nice if a magical van picked me up.
Aspire Tours, done! It was exactly what I wanted. Our guide was very informative, hilarious, and full of passion. Make sure you ask for Kyle, aka the Chipmunk Whisper. We had a great hike, lots of scenery, saw moose (meese), elk, a hawk, and lots of chipmunks. I highly recommend Aspire Tours. They're great!