Along with defencemen Larry Robinson and Serge Savard, Lapointe was a member of the "Big Three" and played a key role in the Canadiens' winning the Stanley Cup six times in 1971, 1973, 1976, 1977, 1978, 1979.

Interestingly, similar to Bernie Geoffrion, his number was raised side by side with the number of other members whose numbers were already retired before him, though this time being the 2 other members of the "Big Three", Serge Savard and Larry Robinson (Savard and Robinson's banner were lowered halfway and were raised back up to the rafters with Lapointe's banner, just like what they did to Bernie Geoffrion and his father-in-law Howie Morenz).

One of his most famous pranks is probably the Vaseline coated handshake with then-Prime Minister Pierre Elliot Trudeau as he was visiting the Canadiens' locker room.

Early into his NHL career, Lapointe was chosen to play in the historic 1972 Summit Series against the USSR.

Lapointe accepted the invitation regardless of the fact his wife would give birth to his first child (Guy Jr.), during the series, while the team was in the USSR.