Mine was Expedition Everest from Disney World, The second one was Big Thunder mountain same area, this is where I got myself a Phobia of Heights, ain't that great! I had to sleep the whole flight back to Atlanta, Georgia.
I had my first roller coaster experience in Everland in South Korea.
Kingda Ka at Six Flag was my first ride in USA. I had to wait about 4 hours in queue.
But the best rides were in Hershey Park, PA. cuz rollercoasters were pretty decent and took no time to get on it(no line).
The Rockin' Rollercoaster at MGM (nowadays known as Hollywood) Studios in Disney World. I just remember jammin' out to Dude Looks Like a Lady and going around loops!