Thematic Trilogies, Duologies, Quartets etc...

Let's see...

To Catch a Thief, Mission: Impossible and The Saint are all shows that you could pull together under criminal enterprises with a Martini-brand spy fiction feel.

There's a running theory that Danger Man, The Prisoner and Ice Station Zebra all follow the same man under a series of differing aliases. Helped in that curiously is the fact that John Drake is teetotal, No. 6 indulges and David Jones is a borderline alcoholic. There's a nice progression there.

Space: 1999, Star Trek: The Motion Picture and The Andromeda Strain all have this very distinctly 1970s approach to science fiction where it's about exploring existentialism almost in a vacuum.

North by Northwest, From Russia with Love and Raiders of the Lost Ark are equally interesting to examine as the thematic predecessor, original and successor to the concept of Bond films. You can see a curious overlap between the three. Lupin III's Voyage to Danger could also be thrown in if you want to see a cross-cultural inspiration.

Yojimbo and Seven Samurai combined with A Fist Full of Dollars and The Magnificent Seven if one is looking for remakes that transform works from differing cultures.

Yeah, his first film as a director Gone Baby Gone, deals with themes like those, and how desperate people can cut corners. I don't want to say too much on it as the film is very rewarding. I guess you'd need to make that an Affleck Brothers loose trilogy rather than just Ben though, since he's nothing to do with Manchester By The Sea.

There are plenty of directors I love who continually go back to their favourite themes, especially Nic Roeg with the idea of persona and identity or Ken Russell with his justaposing of the artistic and the debauched, the holy and the blaspehmous.