There were 5 releases as MackTheKnife said :
- And Now For Something Completely Different (1971)
- Monty Python and the Holy Grail (1975)
- Life of Brian (1979)
- Monty Python Live at the Hollywood Bowl (1982)
- The Meaning of Life (1983)
Although practically, "And Now for Something Completely Different" and "Monty Python Live at the Hollywood Bowl" are not really "movies". The former is remastered collection of their sketches from the first two seasons of "The Flying Circus" while the later is mostly the filmed performance they gave in the “Hollywood Bowl” in 1982 (plus a couple of inserted sketches).
Neither of these introduced any new material, unfortunately. Still, a must-have for any Monty Python fan.