Box Office Bomb: In the U.S. Budget, $170 million. Box office, $113,804,681 (domestic), $222,104,681 (worldwide).
Completely Different Title: The movie was called As Loucas Aventuras de James West (The Crazy Adventures of James West) in Brazil and "Las Aventuras De Jim West" (The Adventures of Jim West) in Latin America.
Development Hell: Hoo boy. The film was pitched as far back as 1992 as a straight-laced film adaptation of the series, to be directed by Richard Donner (who had directed several episodes of the series) and with Mel Gibson slated to play Jim West and a script by Shane Black. The duo ended up making Maverick instead. Tom Cruise was then attached to the project before he decided to revamp Mission: Impossible in its place; only then was the project overhauled into the comedic Will Smith vehicle you see today.
Disowned Adaptation: Robert Conrad, who played Jim West on the original TV series, was very vocal in his dislike of the movie, personally accepting the Razzies it "won". His dislike started when they asked him to do a Remake Cameo as President Grant; on reading the script he described it as an insult to Ross Martin (Artemus Gordon) and Michael Dunn (Dr. Miguelito Loveless). You'd be hardpressed to find a fan of the show who disagrees.
Will Smith has since acknowledged how awful the movie was, especially considering he turned down the role of Neo in The Matrix to make this instead (though he's admitted that that part, at least, wasn't a mistake). He's been a little nicer to this film, however, in the wake of bigger disappointments like After Earth (which came out the same year as The Lone Ranger, which killed the superfluous Western a second time). It helps that his son Jaden didn't mind the film either. (Even on Smith's 1999 album Willennium, when his father asked him which song to put on the CD next. Jaden, a toddler at the time, requested the film's theme song).
Barry Sonnenfeld, Kevin Kline, Salma Hayek, and in fact half the staff at Warner Bros. feel the same way. Hayek in particular thought she was being underused, while Kline considered himself too good of an actor for the finished product.
Despite enjoying his work on the film, Ted Levine admitted that the film's storyline was all over the place due to the constant changes of the script and attributed this along with Will Smith's casting to the film's failure.
S.S. Wilson and Brent Maddock admitted that it wasn't the film they were hoping for due to the constant scriptwriting changes without their knowledge.
Kenneth Branagh self-deprecatingly joked that his accent in this movie might be the worst American accent performed by a British actor.
The Other Marty: Belle was originally cast with, and filmed with British actress Phina Oruche. Reportedly, the chemistry needed for the bathtub love scene wasn't there. The scene was re-cast and re-shot with Garcelle Beauvais. However, Oruche was not told, and found out she was no longer in the movie at the premiere in Los Angeles.