Did you mean on or off property? We don't leave Universal property when we go so can't help you with that.
In my opinion, there isn't a lot to do on Universal property. They do have miniature golf at Citywalk. They have two different courses. There isn't much at Citywalk. They have a few stores and different dining options. We always spend one day at Citywalk, and when we go the parks close relatively early so we go to dinner at Citywalk also. We enjoy Citywalk but we like shopping and eating.
You can also visit the other resorts.
Portofino Bay has singers that come out daily to sing on the balcony. I think it's at 6pm. "Catch this impressive performance of classic opera, festive melodies, and "popera" favorites..." They have seating outside and you can have wine or gelatto while you listen.
Hard Rock has live music and activities by the pool. It's been a while for us so not sure what they offer now.
Those are the only two hotels we stay at so that's all I know. Although, Cabana Bay has a lazy river (we've never been there).
There's also Volcano Bay water park. Not sure if that's one of the parks you are already going to. We have never been since we have plenty of large water parks by our home, but I hear great things about VB.
