the only excursion we did was the catameran and swim with the dolphins. Loved it.
We got the double decker bus into Varadero and spent the day on the beach there with some of the locals, I highly recommend doing this. Great little market in Varadero as well.
I'm not sure if they still offer it but the previous year we went on an excursion to Bay of Pigs. That was fabulous and well worth the money.
Tryp is a beautiful resort and we would go back in a heartbeat.