I would say the best unit was in Montreal when NHL changed the rule about powerplays.
I dont know the names exactly.
I mean: Wow, you are so good that you changed the game rules?! Unit from CC87 came nowhere close to that...
Discuss.
EDIT: Oh, I got it...
Up until the 1956–57 season, a penalized player had to serve his full two-minute term regardless of how many goals were scored by the opposing team. The rule was changed because the Montreal Canadiens had such a powerhouse power-play unit that they frequently scored two or more goals during a power play, with a unit that featured Hall of Famers Jean Beliveau, Maurice "Rocket" Richard, Boom Boom Geoffrion, Bert Olmsted, and Dickie Moore, among others. Three of those players finished among the top four in league scoring during the 1955-56 season, and a fourth finished seventh (Beliveau led the league in goals and points, Richard tied for second in goals and finished third in points, Olmstead led the league in assists and finished fourth in points, and Geoffrion finished fifth in goals and seventh in points).