Monty Python and the Holy Grail (1975)

Made in 1975 for just 229,000 pounds — the cast used coconut shells instead of horses because they could not afford horses — Monty Python and the Holy Grail has earned over 229 million dollars in lifetime revenues and spawned the Tony Award-winning Broadway musical Spamalot in 2005. The British Film Institute named it the 5th greatest British film ever made.