I'm unfazed by rollercoasters when it comes to scares. Same with Mazes at Halloween events, I just buzz of, of other peoples reactions. The only things that get my heart pumping are drop slides like you posted originally - Summit Plummet, King Khajuna and the likes. I've done a good handful of them around the world but when you're stood at the top looking out over the rest of the waterpark and you can't see the slides descent it does get my heart pounding. Then on some you have to 'self release' (I.E propel yourself down) and they always get me, but then in seconds your at the bottom. A great rush! The slides where the bottom drops out don't faze me either.
Summit Plummet view is probably the best one though. See into the distance and to other Disney Parks on the property. Amazing.