Well, I've been riding kiddie rides and kiddie coasters since I was tiny, but the first real coaster experience I remember was Rock n' Roller Coaster at MGM, and Journey to Atlantis at Sea World Orlando when I was eight. Both I rode within the same couple of days of eachother, and though I don't remember the ride experience very well, I do remember coming off of them satisfied with myself for going on them, and satisfied with the actual ride quality.
So yep, those two. Rock n' Roller Coaster was actually my first coaster with inversions. Oh yeah and I literally bawled on both of them, but what do you expect, I'm Taylor.