I agree with Tom and 1Happy Haunt. Honestly, I don't understand why a smooth transition (or any transition) into fantasy world has anything to do with being a classic. Soarin', which I don't consider a classic yet might get that distinction eventually if they every retrofit it with the original Soarin' Over Cali. The update to Soarin' Over the World has been a giant step backwards, but should they go back to the original, I'd say I'd consider it a classic in due time.
Just a thought, at Six Flags Great America there used to be a ride called Cajun Cliffhanger. The ride consisted of stepping into a round "room", standing against a wall, and they shut the entry door. The room would spin faster and faster until you were stuck firmly against the wall, and then the floor would drop out with everyone sticking to the walls. After 30 seconds or so, the floor would come back up, and the spinning would slow to a stop. That ride was removed and there was an outcry because everyone felt it was a "classic" of the park. At no point do you enter a "fantasy world", yet it was a classic in the minds of many. Just sayin'...
For anyone who might not remember or heard of the ride I just mentioned, I found a video of something online that was identical. You can see from the comments below the video how beloved the ride was... to my point.