What is the name of the first vertical loop roller coaster?

The first vertical loop roller coaster is indeed known as "Loop the Loop." This groundbreaking ride debuted at Coney Island in 1901. It was a significant innovation in amusement park attractions, as it introduced the concept of a roller coaster that included a vertical looping element, which had never been seen before. This design paved the way for the evolution of roller coasters, leading to more complex and thrilling designs that include multiple loops, twists, and inversions.

The other titles listed do not relate to the first vertical loop roller coaster. "Greatest Loop," "Vertical Challenge," and "Sky Loop" represent various other coaster concepts, but none hold the historical significance of "Loop the Loop" in terms of being the first to offer the vertical loop experience.