All of the reviews are spot on -- this AMC Theatre is excellent because it's big and never crowded. Although this can sometime hinder the movie-going experience as a fun crowd can make for a fun movie, the lack of a crowd is an overall plus. Good seats are always available and you don't have to worry about getting there early to secure a spot.
Plus, parking is really easy here too. Just park in the structure at the corner of 5th and Fillmore, take the brief walk to the theatre, and remember to validate your parking in the theatre after the movie is over. Covered parking for free is always a win in Phoenix.