Some suggestions from me would be:
1) Medieval Times. Typically mediocre "dinner show" food but the performance itself is a lot of fun -- they do a lot by encouraging audience participation in "cheering for your knight" etc.. Excellent horsemanship, pyrotechnics, and light show, and the falcon that flies from corner to corner of the arena is amazing. Don't go if anyone in your party is prone to asthma, however. It's an indoor arena and the horses kick up a lot of dust. It gets pretty wheezy in there sometimes.
2) Green Valley Petting Farm. Great if you have kids and if it's not too hot outside. It's a very well done petting farm/zoo with a lot of fun animals, a train ride, a hayride, cow-milking, etc. Perfect for a low-key attraction when you need a break from the glitz of the parks.
3) Wikiwa Springs State Park. For those who want to see some of what inland Florida was like before the Disney exodus, check out this park in Apopka (just north of Orlando), which features a swimming in a large natural springs upwelling, canoeing in the Wekiwa river, and a lot of great nature trails.
4) For golfers, take a group lesson at the first-class Faldo training facility at the Marriott Grande Vista. The rates are reasonable if you participate as part of a group, and if you take a full-swing lesson they'll videotape your swing and critique it, and then you get to keep the tape. It can be embarrassing, though, because one of the features on the tape is a split screen with you swinging in slow motion on one side, and Nick Faldo on the other. In my case, it wasn't pretty. (But it was instructive.) Your lesson includes a free half-day of golf on the training course that surrounds the resort -- just nine holes, but interesting and well-maintained.
5) This is way off the beaten path, but my children found it fascinating. If you're going to be travelling to Tampa for any reason during your visit, and if you have kids, I think they might enjoy a detour about 25 miles south of I-4 to Lake Wales. There's a place there called "Spook Hill", which looks like an ordinary small-town side road set on a hill. There's no "attraction" feel to it at all -- to my knowledge the only thing that announces you've found the place is a small sign on the side of the road. Anyway, if you park your car at what looks like the bottom of the incline and take it out of gear, your car will start rolling uphill.

It's just a topographical anomaly, but it is disorienting. (The giveaway is a drainage culvert that is set at what looks like the top of the hill. On rainy days the water will run "uphill" along with the cars.) OK, it's just a minor thrill, and there's precious little else to do in Lake Wales or anywhere else in the area unless you're into camping or bass fishing, so I wouldn't necessarily recommend going way out of your way for this one. My wife grumbled during the detour, and was less than impressed with the "spookiness" effect. My kids, however, loved it.