Most movie theaters have a section of seats in each theater for persons in wheel chairs. These sections generally are in a normal seating row but at the end of the row the last few seats have been removed leaving a large open area for a wheel chair to comfortably fit and watch the show. As long as this area is not otherwise being used by a viewer in a wheel chair, this area can be perfect for safely placing your dog in a down stay away from normal foot traffic beside your seat so you can watch the film.
If the wheel chair seating area is full or otherwise unavailable, the next best solution is to take a regular seat and place your dog in a down stay under your feet. It is not advisable to place your dog in the aisle as that can be a safety hazard in case of a fire or other emergency as well as in a dark unlit theater setting your dog up for being stepped on or otherwise injured.