Godard and Truffaut shared common themes in several of their films, most notably at the height of the French New Wave.
Breathless/ The 400 Blows (misfits)
Band of Outsiders/ Jules and Jim (love triangle)
A Married Woman / The Soft Skin (marital infidelity)
Alphaville / Fahrenheit 451 (sci fi)
Contempt / Day for Night (movie making)
Masculine Feminine/ Stolen Kisses (French youth & Jean Pierre Leaud)
Pierrot le Fou/ Mississippi Mermaid (lovers on the run & Jean Paul Belmondo)