"Star Wars Episode I: The Phantom Menace" released 1999

George Lucas' first prequel to his blockbuster Star Wars trilogy The Phantom Menace was released May 19, 1999.  It starred Liam Neeson as Qui-gon Jinn and Ewan McGregor as Obi-Wan.  It follows the two Jedi as they discover Anakin Skywalker who might bring balance to the Force.

Anthony Daniels appears as C3PO, with Kenny Baker as R2D2 and Frank Oz as Yoda.

Despite poor reviews, it was nominated for three Academy Awards: Best Sound, Best Effects, Sound Effects Editing; and, Best Effects, Video Effects.  John Williams was nominated for a Grammy for his original score.

It won four Guiness World Record Awards for its high box-office success.

"Star Wars Episode II: Attack of the Clones" released 2002

George Lucas' sequel/prequel Star Wars II: Attack of the Clones was released in the US May 16, 2002.  It follows Anakin Skywalker as he begins a forbidden romance with Queen Amidala, and Obi-Wan discovers a secret clone army on a remote planet.

Anthony Daniels (C3PO) and Kenny Baker (R2D2) reprised their roles from the previous four Star Wars movies.  Samuel L. Jackson appeared again as Mace Windu and Jimmy Smits as Ambassador Bail Organa.  Frank Oz provided the voice of Master Yoda.

The movie received an Academy Award nomination for Best Visual Effects.  Unfortunately, it was also nominated for 7 Razzie Awards and won two of them.

"The Dark Crystal" released 1982

Jim Henson's and Frank Oz's visual masterpiece, The Dark Crystal, was released December 17, 1982.  Although it got mixed reviews at first, it has since gained a cult-like following.  The Dark Crystal had groundbreaking animatronics

It received a Saturn Award from the Academy of Science Fiction, Fantasy & Horror Films for Best Fantasy Film.

A prequel has been produced and airing on Netflix.