The original cast, either with Chevy or Murray. Chevy was always kind of a dickhead, though. Belushi was a genius. He could make me laugh with a look.
The cast in the late 80s/early 90s with Mike Meyers, Dana Carvey, Phil Hartman, etc.
Both of those casts consisted of people who were all funny, either individually, or in the roles they filled. The rest of the groups may have had 2-5 players at any time that were funny (sometimes hilarious, like Eddie Murphy or Will Ferrell), but they had people who also sucked on at the same time.
I never thought Chris Farley was funny. It pissed me off when he died and all the Xers and younger were comparing him to Belushi. The only thing they had in common was that they both died of stupidity. Nothing Farley ever did came close to the Samurai.
You had me until you got to Will Ferrell. That guy was a comedic black hole; nothing funny ever escaped from him. To this day, I don't get why anyone finds him funny.