All though i have never been to alton i had to vote for rita. With the launch and the banked turn and the awesome airtime from what i have heard. The launch right into a banked turn which leads to a airtime hill is very unique and a very cool think to put in a rides layout.
I love the speed and theming of Nemesis so thats my favourite. Air is second and followed closely by rita and oblivion. Love them all and Spinball is extremely fun and ripsaw is really good as well especiall when you get soaked.