Denver is a dirty, ugly city. So is Boulder, but in a different way. Area around it though is absolutely beautiful. Having been to most tourist areas of Colorado, and having been to Utah, I'd definitely say Colorado > Utah for tourism.
pretty much nailed it... someone (maybe from here even) said it best - Houston is Austin when it grows up. that said Austin is probably still a better place to visit since it has legitimate tourist attractions (ie the capitol, sixth street, town lake/lake travis, barton springs, etc), excluding cultural attractions which Houston has significantly more. Houston is for most practical purposes a better place to live - substantially better job market (ie high paying jobs), substantially better cultural and ethnic diversity, substantially better access to medical facilities and substantially better access to other desitnations.
