Honestly, I thought *most* of the attractions there were overrated/overpriced, but as a child I would have loved Gatlinburg/Pigeon Forge.
That said, I recommend spending as much time as possible in the park, the aquarium, the space needle (you get 2 rides up for the price of 1 - we did 1 during the day and 1 at night), the tram is kinda expensive but it offers a higher and different view of the area and there is a decent gift shop at the top. There are a ton of putt putt/go cart places in Pigeon Forge.
There is a small pizza place, Ogles, on US-431 just outside of town that was really good. Flapjacks does great breakfast fast and cheap. Bubba Gump is okay if you like seafood. Hard Rock Cafe basically sucked.
Parking is free along River Rd., you have to pay everywhere else.
We used Gatlinburg Log Cabin Rental by Rainbow for our cabin and if we ever go back, we'd use them again.
I'm sure there is more, if I think of anything else I'll let you know