You should try to go to a local village. When I was there I went on this tour I think it was called Sigatoka river safari and it was booked through the resort I was staying at which was the Shangrila Fijian resort on the Coral Coast. That went up the river in a jetboat past a lot of local villages and then went to an actual village where an enormous lunch was prepared with the villagers and it was a really nice experience.
If you went up to Pacific Harbour you can do heaps of activities like the Zipline. The guy who runs that is some American who was talking about doing one around Nadi area which would be a lot more convenient for the regular tourists who don't go for hours around the island. Pacific Harbour is the adrenalin capital of Fiji so if you want to have some fun that is a great place but it all comes at a cost.
Other than that you should make sure you are at one of the decent properties when they have a fire show on as that is really amazing to watch.
Other than that snorkeling can be great out on some of the island resorts and relaxing on the beach. I thought Beachcomber was very over-rated and way over priced for what you get. If you want party atmosphere all the time it is great but if you don't want to be in bed half the day to party all night long then another island would be a much better option.
[ Edit: Edited on 24-Oct-2009, at 20:57 by aharrold45 ]