You can walk to City Walk from your hotel. We usually go to the movies. DH and I have also been known to spend time in Margaritaville listening to the band and having a few margaritas. Several of the clubs have bands in the evenings. Pat O'Briens has the dueling pianos which I think begins a bit earlier than the bands at the other clubs. You can ride the boats to the other resorts and have dinner over there. I recommend the Kitchen over at HRH--you probably will want to have the RPR concierge get you a reservation if you decide to do this. Even if you don't eat at the other resorts, you may just want to check them out--pools, menus, etc.
If you are traveling with kids, NBA City is a favorite spot for dining and playing. When you are at City Walk, remember that your room key will get you preferred seating at many of the restaurants (first available table).
I think you can find stuff to do without venturing off site, but if you have a car at your disposal the possibilities are almost endless. We have often thought of going to the Pirates dinner show, but we are usually to lazy to leave Universal, even though we usually do have a car.