Dragon, The American Museum of Science and Energy in Oak Ridge, where they developed the A bomb is pretty good. Probably about 1 hr drive from Pigeon Forge.
If you like basketball you might see if there's a UT men or women home game (Knoxville). The women games are just as fun as the men's. There's also the women basketball hall of fame but I've never been there.
The Ripley's Aquarium in Gatlinberg is cool, especially if you have kids. Knoxville Zoo is pretty good for kids.
Check to see what's scheduled for the Tennessee Theatre in Knoxville, a great place to see a show. Bill Cosby and Brian Setzer Orchestra are coming some time in Dec. There's also a lot of plays I think.
For restaurants in Knoxville my favorites are
Tomato Head (Downtown old city, pizza)
Nama Sushi Bar (best sushi)
Crown and Goose (pub, downtown)
Long's drugstore (best place for lunch)
By the track bistro (best fancy place)
Calhoun's (BBQ, brew their own beer)