Took a quick look at your site (nice work, btw)--given what I saw of your style there, I'd recommend the following based on the trip I took there last fall:
Clingman's Dome (yes, you'll be one of a dozen or more photogs lined up with your red ringed lenses, but it really is the best place to capture a sunset). Don't bother hiking up to the point unless you want to say you did it, though, as there isn't a decent vantage point to the west from up there. The view from the parking lot and sidewalk is much better.)
Spruce Flats Falls--probably my favorite hike from when I went. Moderately strenuous compared to others, but better falls there than in other places, in my view, and it won't be as crowded.
Abrams Falls--This is a hike off the Cades Cove loop--if you are going on a weekend, probably best to steer clear, but a large volume of water makes this one decent. A couple of playful otters entertained us when we were there
Little River--easy hike, stays along the river for long stretches, so you'll see trout fisherman and little cascades throughout. The best part of the hike for me, though, was the abandoned vacation homes that line the first half mile.
Alum Cave Bluff--Decent views throughout, cascades, and some interesting rock formations, one of which you walk through on the way up. Also a popular hike, though, so if you are looking to avoid crowds, this probably isn't the one for you.
Bud Ogle Home--a pleasant surprise, very close to downtown Gatlinburg and all of the tourist traps that, unfortunately, you'll probably have to drive through more than once.
One or two others I would have liked to make but didn't: Chimney Tops and Charlie's Bunion, but, alas, not enough time, and the kids were with, so the longer hike (Bunion) we didn't manage.
Hope that helps.