I like the CityWalk at Universal Orlando, there are great restaurants, shops, nightlife / clubs, and a huge movie theater. Last trip down we ate dinner at Cafe Tu Tu Tango near Universal, a fun place to eat. We also did Gatorland on our last trip, a smaller and older theme park, a little on the hokey side but everyone had a good time and the kids really enjoyed seeing the various critters and got to hold a snake and a lizard, not sure how adults would enjoy it though. Other possibilities include fishing, sailing, biking, golf, a guided fishing tour on the coast. One of the coolest things we've done in Orlando is actually go out and visit KSC - Kennedy Space Center. My wife thought I was crazy and laughed at me all the way to KSC, and once we were there said it was one of the coolest things we've ever done in Florida!

They take you around the Canaveral space center on buses and you stop in different buildings and see all things related to NASA, including the space station center where they are building parts of it, we saw an Apollo 11 rocket, stood in the original mission control launch center, and there are 2 different IMAX movies, and more. KSC is a full, long day, we didn't allow nearly enough time there to even see all of it (we got there around 1pm, not enough time!).
Disney also has some world class spas if you want to indulge yourself. Cirque du Soleil at Downtown Disney was superb. Want to drive a real live Nascar race car? Then the Richard Petty driving experience is for you at Disney. There are airboat tours and rentals. Hot springs and boat tours and rentals. Rent a harley, go go carting, mini golfing, helicopter tours, places to pick your own fruit / oranges, local winery tours, horseback riding, surfing lessons, snorkeling, water skiing, parasailing, fitness centers, and probably a whole lot more ....
Here's a
link to a ton of it.