There are just a few options with a cover charge. For instance, the Circque Dreams show I recently paid extra for on the Norwegian Epic was well worth the extra cost. With this particular show, there are two different cover charges. The more expensive one serves a very good steak dinner, and seating is on the main floor where all the action takes place. The lower fee is for seating above the action, which in my honest opinion, would provide a better view. I am returning to the Epic in about 10 days, and have booked the show again - this time with the upper level seating. I'll let you know what I think.
If you're not interested in entertainment with a cover charge, there are plenty of great shows and activities that are complimentary.