Kingda Ka Opens at Six Flags Great Adventure

After it drops a record-breaking 456-feet down the other side of the top-hat tower, Kingda Ka navigates a second 129-foot hill designed to deliver some gravity-defying airtime (that out-of-your-seat, butterflies-in-your-stomach sensation). With all of its pent-up energy, I'd imagine the coaster's negative Gs must be pretty intense.