Bastian Appearances
Truthfully, the original Neverending Story is such a benchmark in moviemaking that it's not really fair to say that the rest of the series isn't as good as the orignal. They're perfectly serviceable children's adventure movies, they're just not as good as one of the greatest movies ever made.
The original Neverending Story from 1984 was the first ever english-language movie by famed German filmmaker Wolfgang Peterson, who made this movie right after Das Boot. At the time of it's filming it was the most expensive film ever produced outside the US or the Soviet Union. Bastian is played by Barret Oliver, and the image of him riding Falkor at the end of the movie is something that's imbedded into my imagination. This is one of those incredibly rare movies (Labyrinth, Dark Crystal, Princess Bride) that continue to feel like some kind of magic.
1990's The Neverending Story II: The Next Chapter was another German production with an entirely new cast. Bastian was played by 13-year-old former child model Jonathan Brandis, just before the start of his status as a teen heartthrob. The movie used some elements from the original novel, but was largely a new story.
The Neverending Story III was a 1994 American/German production with another entirely new story. It starred Jason James Richter, who had risen to stardom the year prior in the movie Free Willy, although the movie is more often noted as one of the earliest film roles for Jack Black as the bully and villain Slip.
The 24-episode animated series The Neverending Story aired on HBO in 1996, and eshewed closer to the plot of the original novel. Bastion was voiced by Christopher Bell.
Tales from the Neverending Story was a Canadian-produced 24-episode single-season series that aired on HBO in 2001 starring Mark Rendall as Bastion. It used the novel as a guide but took liberties with the source material, reshuffling events and adding new characters. I'm actually a fan of this series, particularly it's original character Fly Girl, who deserves a larger fanbase.