The thing about Nemesis is that it is so much more than it appears to be. Unless you have ridden it you can have no idea of how the clever landscaping and design not only draw you in, (the line to ride snaking within the ride, past the blood-red waterfalls, building the anticipation), but enhance every moment of the ride itself. In sheer thrill terms it packs a bigger punch than any other coaster I've been on, regardless of size, but it still, after 20 years, delights the eyes and makes the heart soar. Thematically it is utterly coherent, the track acting as the restraints for the alien creature that was discovered during excavations, and it looks as good as any mountain that Disney has created.
I have to vote Nemesis. It is one of the finest coasters on the planet and deserves recognition as such.