Do what you want to do, go where you want to go for your birthday. My niece chose Gold Reef City. They went on every ride they could, they were even prepared to queue, no problem. Dumbo, dinosaurs, Flintstones, teacups, hot air balloons, bumper cars, safari train, and so on. We crawled across the old steam trains and visited the petting zoo. We had lunch out doors and were entertained with dancing - what great rhythm, what a wonderful vibe. Then back for more rides. Eventually we were all exhausted and had to take the train to the exit because we couldn't take another step (although, of course, we did). What a fabulous day we had.
There is still something so magical about the carousel. I wish it were for adults too.