In your opinion, what is the prettiest spring blooming tree in East Tennessee? I'm looking for something with really bright pink/red blooms.
If you have kids, which is your favorite....I don't know how to pick just one. I can say that if I were picking a tree for my yard, I'd look at other factors besides just which one was prettiest. For instance, if I were picking a crabapple, I'd be sure to pick a broad-spectrum disease resistant cultivar (I could give you a list if you decided to go with a crabapple). I probably wouldn't choose a cherry/Prunus, because they are generally pest- and disease-proned and short-lived. If I were going to plant a redbud, I'd be very careful to choose one with a good branching habit to start with, and make sure I was committed to training it well to avoid poor crotch angles.
I am impressed by some of the large beautiful deciduous magnolias I see occasionally. I don't know that they are the most beautiful, but they're definitely one of my favorites.
You know, for years I thought Yoshino cherries were just the most breathtaking, with their glowing, almost ethereal pale blossoms... But now I'm glad I have a purple leaf plum instead. The blooms are fragrant, and even when they are fading, the rich color of the emerging leaves keeps the tree looking attractive and interesting. I agree with Brandon that the Prunus family has it's share of problems, but sometimes they're just irresistible;)
There are a couple trees in my neighborhood that have an intense fuschia pink bloom, but I'm not sure if they're crabapples or cherries. They are traffic stoppers for sure though!
Otherwise a tulip magnolia should give you some Spring blooming options in your preferred color.
For your requested color range, redbuds are hard to beat. They are also both native and quite drought/heat tolerant. Forest Pansy is a nice variety with red foliage (at least through spring). Red buckeye is also nice.
Redbuds are by far my favorite spring flowering tree. Dogwoods get all the glory but Redbuds imho outshine them by far! Given a good placement (full sun,plenty of room, well fertilized, etc) a Redbud tree not only blooms sooner in the spring (usually before anything else), but it also has a very showy display or lovely purple flowers everywhere! Not many trees that I know of can shoot flowers out from branches like a Redbud.
The one drawback of the Redbud is that they are a shortlived tree and require alot of deadwooding (removal of dead/dying branches). But if you don't mind going that extra yard, you WILL be rewarded with an early spring show that will make your neighbors envious!