Maybe someone has already posted a thread like this, I don't know, but ratings come up in discussion at lot, so I thought I'd clarify the subject with the following links:

http://www.angelfire.com/ny2/televisioncity/7580.html
http://www.angelfire.com/ny2/televisioncity/8085.html

TC: The first season didn't place. Perhaps it didn't count because it was a mini-season? The rest of the Chrissy era, the show was in the top 5. Then, they replaced Chrissy with Cindy, and the show plummeted to 15th. Then, Terri came on board, and the show jumped back up to the top 5. Continued to do well in Terri's next season. In the final season, the ratings dropped through the floor.

Ropers: They were (surprisingly, to my mind) in the top 10 their first season. Then, they fell of the map in their second and final season.

TAC: Never cracked the top 20. In fact, it got the lowest ratings of any of the TC-related shows, in any season.

Maybe someone has already posted a thread like this, I don't know, but ratings come up in discussion at lot, so I thought I'd clarify the subject with the following links:

http://www.angelfire.com/ny2/televisioncity/7580.html
http://www.angelfire.com/ny2/televisioncity/8085.html

TC: The first season didn't place. Perhaps it didn't count because it was a mini-season? The rest of the Chrissy era, the show was in the top 5. Then, they replaced Chrissy with Cindy, and the show plummeted to 15th. Then, Terri came on board, and the show jumped back up to the top 5. Continued to do well in Terri's next season. In the final season, the ratings dropped through the floor.

Ropers: They were (surprisingly, to my mind) in the top 10 their first season. Then, they fell of the map in their second and final season.

TAC: Never cracked the top 20. In fact, it got the lowest ratings of any of the TC-related shows, in any season.

Yes, Three's Company was ranked by Nielsen as a series in it's first season, when it finished in 11th place. Here's how the series ranked in the ratings each season:

Season One ('77): #11
Season Two ('77-'78): #3
Season Three ('78-'79): #2
Season Four ('79-'80): #2
Season Five ('80-'81): #9
Season Six ('81-'82): #4
Season Seven ('82-'83): #6
Season Eight ('83-'84): #35
Three's a Crowd ('84-'85):#46

Check out the show information section for Nielsen rankings:

http://www.sitcomsonline.com/jacksbistro/

Check out the show information section for Nielsen rankings:

http://www.sitcomsonline.com/jacksbistro/

I just looked and I see several discrepancies in the rankings compared to the best sources I can find, including books. What was the source used to come up with that information? Here are the discrepancies I see:

1978-79 - #1 (should be #2)
http://classic-tv.com/ratings/1978-1979-tv-show-ratings.html
http://www.super70s.com/super70s/tv/1978-79.asp
http://www.classictvhits.com/tvratings/1978.htm
http://en.wikipedia.org/wiki/1978%E2%80%9379_United_States_network_television_schedule

1980-81 - #8 (should be #9)
http://classic-tv.com/ratings/1980-1981-tv-show-ratings.html
http://www.classictvhits.com/tvratings/1980.htm
http://www.awesome80s.com/Awesome80s/TV/1980-81.asp
http://en.wikipedia.org/wiki/1980%E2%80%9381_United_States_network_television_schedule

1983-84 - #31 (should be #35)
http://en.wikipedia.org/wiki/1983%E2%80%9384_United_States_network_television_schedule

1984-85 - #38 (should be #46)
http://en.wikipedia.org/wiki/1984%E2%80%9385_United_States_network_television_schedule

Check out the Chris Mann book. We go by that. He has the correct research. Some of those sites go back and forth with HH rating and number of households watching...

L&S was #1 in 1978-79 but it and TC were in a vertual tie. I've seen different sources claim each as #1. In 1980-81 TC was tied for #8 with House Calls. I don't know about the other two seasons in question but I did follow TAC ratings at the time and I think #38 is closer to the truth. Most weeks it was ranked in the 30's.

would it be crazy to say the ratings declined because Suzanne Somers left?

would it be crazy to say the ratings declined because Suzanne Somers left?
It originally did but it increased again when Priscilla Barnes joined the cast.

Check out the Chris Mann book. We go by that. He has the correct research. Some of those sites go back and forth with HH rating and number of households watching...

I don't think Chris Mann has written on anything but Three's Company, so his information may be biased. It's a little curious that all the discrepancies in his rankings favor Three's Company. A better source is Tim Brooks and Earle F. Marsh's The Complete Directory to Prime Time Network and Cable TV Shows. They first put that book out some 30 years ago and continually update it. It covers all TV, so there's no bias. And the ratings information they have, as well as the other references I listed, are consistent with one another. I remember very well that the 1978-79 season that Laverne & Shirley was declared the #1 show of the season; it was a topic of discussion at school (and I'm no fan of that show at all, by the way). This is the first time I've ever seen Three's Company listed as #1 that season. Here's still another source:
http://www.museum.tv/eotvsection.php?entrycode=threescompa