Disneyland's lead up from the stretch room to the loading platform add a lot of suspense to a rather tame ride. I have to give the nod to Disneyland's version.
(Although I go to Disneyland frequently, my one visit to the Magic Kingdom in 1997 was only a half-day, and we only had time to rush around the park and go on about five rides.)
WDW's version just comes off as a better paced, more thought out version.
The WDW version lost a few points this past year though. The new additions (the interactive queue and the CGI hitchhiking ghosts) SUCK, in my opinion. They're too kiddie-oriented and don't match the style of the rest of the attraction.