I agree with tickets to a play - that’s a really fun evening out and something you can do together or with a group. 

Movie tickets are more spontaneous and not so much a gift.  Tickets to a film festival are a good one, though  - I did that a few years ago.  My mom and I always watch TCM when we are together, so I got us passes to their film festival in Los Angeles.  She flew out and we had great fun - we saw movies in some historic theaters and she got to see celebrities during the panels.  She really enjoyed the Michael Douglas Q&A after THE CHINA SYNDROME.