My top three activities would be:
1) check out the north and south end of the island in a golfcart
2) Rent a small hobie cat and sail up and down the island for an afternoon
3) go parasailing

Top 5 places to eat would be (not necessarilty in this order):
1) Rubies for breakfast
2) Cannibal's
3) Bluewater Grill
4) Jade Garden
5) Mambo's

Top 5 party places(not necessarily in this order):
1) Cannibal's
2) BC's
3) Hideaway Sports Bar
4) Palapa Bar
5) The beach in front of Ramon's