It's a close call between Nemesis and Oblivion, but I think Oblivion just scrapes it for me. I get scared every single time I ride it (42 times now, but who's counting?). The whole ride experience is delivered perfectly, as soon as you enter X-Sector you can sense a certain kind of atmosphere that seems to be absent from other areas of the park, and the themeing all fits in with the brand extremely well. The queue line perfectly sets the mood with the videos, and the fact that you can see the innards of the station and underneath of the cars from an indoor part of the queue is a very nice touch. The force during the drop never fails to put a huge grin on my face and I am always left craving another ride. (Also orange and black are my favourite colours
) I think standing alone with no themeing, and just judging by the coaster, Nemesis would win, but taking into account the whole experience, Oblivion is the winner in my books.