Denver Area Special Occasion
Both are excellent choices, but I think Frasca might feel a bit more "special" - atmosphere and service are considerably more refined, and the wine program is far superior in case you're thinking about treating yourself to a special bottle. Fruition's food is wonderful but it has more of a casual, neighborhood feel while Frasca is a bona fide destination restaurant. Have fun!
Rcurtism nailed the difference, IMHO, but I'll trhow another F-restaurant into the special occasion mix. Boulder's Flagstaff House also has refined food, exceptional service and great views. You can't go wrong w/ any of these three.
Flagstaff House Restaurant
1138 Flagstaff Dr, Boulder, CO 80302