Boulder Dash, very closely followed by Phoenix. Although after having ridden Phoenix on the "famed" third row seat and being launched out of my seat during the entire course of the ride and even landing on the seat divider at the end of the seemingly endless bunny hop finale, I might even have to place Phoenix ahead of Boulder Dash.
And yep, I've been on all the top contenders - El Toro, Voyage, Ravine Flyer II, etc. Phoenix beats them all.