The Savoy 16 (part of Goodrich Quality Theaters) has started their Free Spring Matinees again this weekend with Are We Done Yet? The listing is pretty good this season.
All shows are Sat and Sun at 10am and 11am. If it is a really popular movie, you might have to go early and get tickets (the year they showed Harry Potter, it was a mess). It really is free, although of course the concession stand is open for business. They also have an intermission ... sometimes we leave at this point if the little ones are done.
*Also note, Savoy 16 has shortened their commercial/preview times to closer to 10mins. So, you actually have to be on time to movies again!