Spinout, the only reason you find a regular Top Spin so boring is because you haven't one with a decent program. Stop by Kennywood, or if still exists, ride the one owned by Strates Shows. I think I counted twenty-one flips last year.
A Tilt-a-Whirl amazing and/or unique? Granted they can be fun, but amazing? And again, a Wipeout?
My unique choice would be the Huss Flipper owned by Reithoffer Shows, because you won't find another one in the United States.
My amazing choice would be Street Fighter (also known as Extreme) made by Technical Park. It destroys all other inward-facing pendulum-based rides. The airtime is insane.
I always thought the Boomerangs were pretty amazing, and very unique. I rode one at the Dixie Classic Fair back in 1993 but haven't seen one since. I have always been curious if it was still in operation.
No thrill ride has ever beat the Zipper in my eyes. 100 percent undefined, unrestrained, unpredictable disorientation. In such a relatively simple package. I only wish there were more around than just depending on a travelling show to bring one.
Don't ever ride one with anything in your pockets that you will ever need to see again. :)
I think the most unique flat I've seen pics of -- which unfortunately I can only seem to find one small photo of -- is the Wheel Burrow that was at SFOG. It was two Chance Skydivers that rotated horizontally around each other.