Vortex at Carowinds
I'd probably say I liked Scorcher better. Chang would be my second pick. I think the genre is better suited to the smaller designs though. The Scorcher while not having many inversions, has some great turns and force changes in its layout that make it incredibly fun. You get alot of float on the 90 degree banks and the left turn down into the helix after the first turn around.
I haven't ridden Riddler, but it seems people consider Riddler and the Scorcher to be the best of the bunch.
Edited for photowhoring fun!