What region has the best coaster collection?

Botanically speaking:
Northwest Ohio = midwest
Southeast Ohio = south/appalachia
anywhere else = gradients between the two

Geographically speaking:
Pennsylvania = Mid Atlantic (along with NY, NJ, MD)

No StandUp Fan you did not start anything with the geography statements you made, nor are you geography illiterate. Everyone has differences on where the mid-west ends, and begins. I do agree with your choices of Indiana, Illinois, Ohio, Missouri, and PA. This region offers a nice variety of coasters.

Philadelphia. Less than four hours from SFGadv, SFA, Dorney, Hershey, Knobels, Sesame Place, Coney, the Jersey Shore,etc.
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Peace, Love, and Rollercoasters.........we need more of all three.