The Appalachian trail is pretty great!
Seconded!
John Muir
Foothills Trail on the NC/SC border through the Blue Ridge Mountains, I believe it is possible to connect to the Appalachian trail now for longer hikes all the way up the east coast.
The favorite one I’ve actually hiked is the River to River trail in southern Illinois. The fact that it’s the only one I’ve hiked might have something to do with that, though the eastern half is pretty darned scenic (especially for a midwest trail).
I’ll always be fond of the PCT but I’m sure it’s because it was my first. The 500 mile section I did on the AT is all I ever need to do of that trail… I much prefer the grand vistas of the PCT (and the switchbacks!) compared to the green tunnel which heads straight up the sides of rocky hills.