Well Seiverville would be my last pick for the area. I just like staying in Gatlinburg much better(although it depends on what you are doing). Take note-to drive from Sevierville through Pigeon Forge and Gatlinburg will take you a while-go early to avoid the huge huge traffic problems. That said, you will be fine in Sevierville.

My picks are Smoky Mountains-specifically-Cades Cove/Abram Falls, Grotto Falls, Laurell Falls, and Klingmans Dome hikes. Also hiking and spending the night at Leconte(to late for reservations for this year for this one).

Be sure and see if the "fireflies" are there(most likely late May or early June). These fireflies are unique because they all flash in unison at the same time. There are only two places in the world they do this. It only last for about 10 days though.

Parrot Mountain is really interesting.

Ziplinning is a must do in the area. I would go with Climbworks Canopy. There are about 5 different companies and they are all similar(I think anyway), but Climbworks seems to be the best accoroding to most sites/surveys.

Kids would love Zorb

Dollywood

I like to eat at Kilwins for ice cream, Cakes by Bakin Bishop for sweet snacks, Tomato Head in Knoxville. Applebarn-decent food and good apple fritters. Old Pottery Mill and also vist the square while there. Finally, I always eat at Hardrock Cafe when in Gatlinburg. Something about this HR just seems better than the rest of them. Plus, they allow for reservations, so you won't be stuck standing in line forever at dinner.

You might also consider driving thru the park over to the Carolina side and visit The Biltmore.

http://www.fodors.com/community/united-states/ziplines-zorb-pancakes-and-parrots.cfm

Above is a link to our latest trip report/photos there last year the 1st week in June. I am going back this year over Memorial Day weekend, as the fireflies were already gone by June this past year. We've been several times and there is plenty of options of things to do