The first film version, directed by Herbert Brenon was released in 1926 starring Warren Baxter, Lois Wilson, and Neil Hamilton as Jay Gatsby, Daisy Buchanan, and Nick Carroway respectively. The film was released as a silent film during the time of the budding film industry. However, no copy of the original film has ever surfaced and as such has fallen into the realms of movie history.
The second film adaptation of The Great Gatsby came out in 1949 by director Elliott Nugent with Alan Ladd as Jay Gatsby, Betty Field as Daisy Buchanan, and Macdonald Carey as Nicholas "Nick" Carroway. This version however is widely considered to be the worst of all adaptations of the film.
The third and arguably most famous version of The Great Gatsby is the 1974 version directed by Jack Clayton and starring Robert Redford, Mia Farrow, and Sam Waterson as Jay Gatsby, Daisy Buchanan, and Nick Carroway respectively. This version won two Oscars as well as nominations and wins for various other awards.
The final version is the 2000 version directed by Robert Markowitz and starring Mira Sorvino, Toby Stephans, and Paul Rudd, as Daisy, Gatsby, and Nick respectively. This film flew relatively low under the radar when it first came out and as such is still surpassed by the 1974 version and of course by the book itself.
All information courtesy of http://www.imdb.com