Before we begin, I want to point out that this methodology is extremely flawed. Humor can't be objectified, etc., etc., but even if it could be, this would be a deeply imperfect way to decide which SNL cast members reign supreme. I'll try to list the major flaws with these methods as they appear, but there are countless others you'll think of-- please know in advance that you are correct.
OK, with that in mind, let's try using SNL episode ratings (via IMDB, scraped using rvest) to find out which cast members have the highest average episode rating:
1 - John Belushi - 7.142
T2 - Noël Wells - 7.100
T2 - John Milhiser - 7.100
T2 - Brooks Wheelan - 7.100
T5 - Siobhan Fallon - 7.060
T5 - Dan Aykroyd - 7.060
T7 - Laraine Newman - 7.055
T7 - Jane Curtin - 7.055
9 - Gilda Radner - 7.050
10 - Paul Shaffer - 7.02
John Belushi seems like a reasonable #1, so this method sooooort of lines up with intuition, but there's an obvious flaw: cast members who didn't rack up many episodes are able to ride their small sample sizes to the top. This batch of data is already restricted to cast members who lasted at least 15 episodes, but let's bump that qualifying number up. Let's look at the highest average episode rating among cast members who were on the show for at least 50 episodes:
1 - John Belushi - 7.142
2 - Dan Aykroyd - 7.060
T3 - Laraine Newman - 7.055
T3 - Jane Curtin - 7.055
5 - Gilda Radner - 7.050
6 - Garrett Morris - 7.010
7 - Chevy Chase - 7.000
8 - Bill Murray - 6.988
9 - Nasim Pedrad - 6.929
T10 - Jay Pharaoh - 6.920
T10 - Taran Killam - 6.920
This is a much more reasonable list. The clear downside is that we can't measure cast members' contributions, so we're really just looking at which players coincided with beloved eras, but short of weighting by sketches appeared in (which is possible but would require much more coding and still be imperfect), this is the best we can hope to do. Looking at this ranking calls to mind Rolling Stone's greatest songs list, which posits that the six greatest songs in human history all came out within a ten-year span of each other during the '60s and '70s.
But we can do one better than this method. This time around, let's pretend that after every show, Lorne Michaels breaks that episode's IMDB rating into pieces and gives a piece to everyone who appeared in the episode (including hosts/guest stars). Then the cast place their star pieces in the bank and accumulate them over the course of their tenure on the show.
So if an episode gets 7 stars on IMDB and 10 people appeared in it, they each get 0.7 stars. And if a cast member gets 0.7 stars each episode x a 20 episode tenure, their star total would be 14 stars.
The two advantages to this method are a) it's cumulative, so longevity is prized over a flukily small sample, and b) it provides a verrrrry rough approximation of contribution-- each cast member gets a smaller slice of the episode's pie if there are a ton of other cast members OR if celebrities showed up to shoulder some of the load (as is increasingly the case during cold opens).
With this in mind, let's look at the all-time leaders in cumulative star-shares:
1 - Kenan Thompson - 95.482
2 - Darrell Hammond - 72.121
3 - Seth Meyers - 67.527
4 - Fred Armisen - 63.013
5 - Bobby Moynihan - 52.602
6 - Jason Sudeikis - 48.945
7 - Kate McKinnon - 48.357
8 - Tim Meadows - 48.150
9 - Kevin Nealon - 47.958
T10 - Cecily Strong - 47.156
T10 - Aidy Bryant - 47.156
Was there truly any doubt that Kenan would be #1? Even if you don't think he's the Michael Jordan of SNL, he's at least the Kareem Abdul-Jabbar: a consistent and long-tenured performer whose career numbers are unparalleled. I should also note that Darrell Hammond's star-shares do not count his episodes as announcer. If we allowed him to earn stars for those episodes, he would be #1 among cast members. (But by this same token, Don Pardo would be even higher.)
A small addendum: Let's say that instead of divvying up each show's rating between cast members, everyone gets the full star rating of any episode they appeared in. How would that change the rankings? Not much. The top five remain the same, then there's a bit of reshuffling:
6 - Kate McKinnon - 1295.2
T7 - Cecily Strong - 1259.2
T7 - Aidy Bryant - 1259.2
9 - Jason Sudeikis - 1211.7
10 - Tim Meadows - 1181.5
For fun: the top SNL 10 seasons of all time, according to IMDB episode ratings:
1 - Season Eight (1982-1983) - 7.311
2 - Season Three (1977-1978) - 7.285
3 - Season Two (1976-1977) - 7.262
4 - Season Thirty Three (2007-2008) - 7.189
5 - Season Four (1978-1979) - 7.175
6 - Season Thirty Seven (2011-2012) - 7.164
7 - Season Thirty Nine (2013-2014) - 7.143
8 - Season One (1975-1976) - 7.111
9 - Season Seventeen (1991-1992) - 7.079
10 - Season Thirty Two (2006-2007) - 7.062
And the bottom five:
1 - Season Twenty Two (1996-1997) - 5.388
2 - Season Twenty Eight (2002-2003) - 5.452
3 - Season Twenty Three (1997-1998) - 5.671
4 - Season Twenty Nine (2003-2004) - 5.698
5 - Season Twenty Four (1998-1999) - 5.738

ok now who are the worst 😈