For a fun night out try Diamond Head Theatre. Different shows offer varied level of performance, but for the most part you will have a good night of entertainment. Of the 10 or so shows I've been to, I've left at intermission probably 2 times, but this is mostly due to my early bedtime. The shows are usually musicals.
Don't bother getting the more expensive tickets, as all the seats are pretty close as the theater is small. Dinner & a show are a great date.