Happy 70th Terry!
Terry is best known for 2 things: (1) being the only member of the Monty Python troupe that was not born in Great Britain, and (2) being a great director. This list is not a list of the best movies he has acted in but a list of what I think are the best movies that have had him as their director.
Monty Python and the Holy Grail (1975)
Terry actually co-directed this movie with fellow Python member Terry Jones.
This movie was actually not based on sketches from their TV series, as were previous Python movies. It is basically a spoof of King Arthur and the Knights of the Round Table and their quest for the titular Grail.
Besides directing this film, Terry also starred in it as Patsy (King Arthur's assistant), the Bridgekeeper, and the Green Knight. It also stars Graham Chapman as King Arthur, John Cleese as Sir Lancelot, Eric Idle as Sir Robin, Terry Jones as Sir Bedevere, and Michael Palin as Sir Galahad.
12 Monkeys (1995)
This is one of my favorite time-travel based movies. It is loosely based on a short film produced in 1962 titled La Jetee (or The Pier).
It is about a convict in a post-apocalyptic future that travels in time to help figure out what caused a world-wide pandemic that forced the entire remaining population of the Earth underground.
It stars Bruce Willis as James Cole (the convict), Madeleine Stowe as Dr Kathryn Railly, a psychiatrist from the present-time (not the future) that gets kidnapped by James Cole, Brad Pitt as Jeffrey, an inmate of a mental facility in the present that James Cole ends up in, and Christopher Plummer, as Dr Goines, the father of Jeffrey.
Fear and Loathing in Las Vegas (1998)
This film was based on Hunter S. Thompson's novel of the same name.
It stars Johnny Depp as Raoul Duke and Benecio Del Toro as Dr. Gonzo. It also has cameos by Tobey Maguire, Ellen Barkin, Christian Ricci, Gary Busey, Mark Harmon, Cameron Diaz, Lyle Lovett, Flea, and Harry Dean Stanton.