Space Mountain is a great attraction and a prefect example of WDI's ability to make a ride better than the sum of its parts.
Having written that praise, Splash Mountain is truly a wonder, the ultimate flume attraction on this planet. It gets my vote, fair and square.
Splash Mountain is pretty good, but DL SM is fantastic.
Ultimately, I went for Splash. I can't explain exactly why. It feels a little more dilapidated than it used to, and yet it still packs so much charm.
That, and it led to one of the greatest theme park quirks of all time, Flash Mountain.