Lots of people love Jellyrolls at Boardwalk. I haven't been, but read it doesn't it get going until about 9pm and you should be there then to get a seat because it fills up.
Aside from La Nouba, DTD is always fun with all the bars and restaurants around. Last time we were there was on a Friday in September and they had some outdoor entertainment at Pleasure Island. DTD is crowded on the weekends but there's a lot going on.
If you're near MK, you could also watch the electric boat parade and Wishes from the beach at Poly. We did that one night, and then had a drink at the bar after to let the crowds clear out. It was a nice way to watch it, and they play the music that goes with it.
In case you see anything about Yeehaw Bob at POR, he is a lounge act at POR who plays there certain nights of the week. While it's cute, as two adults, we didn't enjoy it. It was silly, family humor which is to be expected. I wouldn't make a special trip there to see his show without kids.