I live north of Denver in Fort Collins. I am originally from New Jersey with family from NY city, so I know my east coast pizza. I can recommend a few places:
1. One of the best, believe it or not, is in Cheyenne, Wyoming. It is called Losteria Mondello.
1507 Stillwater Ave # D, Cheyenne, WY 82009 Phone: (307) 778-6068.
He is an Italian native of Palermo, italy. Originally had a pizza place in New Jersey, and is now in Cheyenne (must be the witness protection program). I actually like his pizza the best in Colorado and Wyoming. They also have a restaraunt. I sit and talk with his father quit a bit about the time I spent in Italy with the military.
2. Fort Collins, CO -
Pulcinellas Pizza 1614 Oakridge Dr # B, Fort Collins, CO 80525
Phone: (970) 377-8282
Positano's Pizzeria Address: 3645 S College Ave # 5, Fort Collins, CO 80525
Phone: (970) 207-9935
Started out together, then split. Originally from Naples, Italy. Good east coast pizza.
3. Denver, CO - Fuhgidabowdid Pizzeria 2041 S University Blvd, Denver, CO 80210
Phone: (303) 777-5200
Originally from Brooklyn - good pizza. Down the street from Denver University (DU). I am just now working my way through the Denver places, I am sure there are more.
Let me know what you think if you make it to one of these places.