I haven't been up to International Drive in awhile, and Orlando changes quicker than most places on what is there and not there, but these are the ones I can think of that were there the last time I was there. For the architecture alone (upside down house, house falling into sinkhole), it's worth driving up on International just for that. The best thing to do if you have a car, is to stop at one of the restaurants outside WDW and get one of the tourist books. They have a lot of these listed and often have discounts as well.
Guiness Book of Records
Ripley's Believe It Or Not
The IMAX theatre at Pointe Orlando
Wet and Wild
Skull Kingdom
Bells (sp?) Factory Outlet - which has a lot of cool shops including a Disney Character Warehouse store where you can buy souvenirs very cheap there, much cheaper than in the parks.
Amazing Animals - A small place, but they do have some cool exhibits like face to face with some big cats (tigers/panthers).
Race Rock restaurant
Wonderworks - I would just look at the outside building and skip the inside, which is a bad science museum. Your money would be better spent at the:
Orlando Science Center - A multistory science museum with a lot of hands on exhibits for the kids.
Mystery Fun House - Which I'm not sure is still there, but it was the last time we were there.
On US-192:
Old Town which has a lot of shops and museums as well as carnival type rides and some nights, a classic car show.
WaterMania
Several MiniGolf courses (Congo River Golf is pretty awesome).
Medieval Times Dinner Show
Arabian Nights Dinner Show
The Sky Coaster
About 50 miles east, the Kennedy Space Center. 70 miles west, Busch Gardens...