Ever notice how when a company or creator or whatever has three main franchises, the third seems to be less popular?
Like with Seth MacFarlane's shows, Family Guy and American Dad have both on on the air the longest and remain on the air, while The Cleveland Show only had a few seasons and is no longer in production? Though this might be a lesser example, as that's a spin-off from Family Guy and it seems that one's more well-liked than American Dad (even though Cleveland no longer has new episodes and AD is still... Oh, never mind).
And with George of the Jungle, there's three main segments. George of the Jungle is the title segment, and the only one to have been made into movies. And then there's Super Chicken, which I think also has a similar fan following. And then there's Tom Slick, which seems to be the least-interesting and most-forgotten of the three segments. The Moose That Roared mentions a pitch tape for a new Rocky and Bullwinkle show, which would have included new George of the Jungle and Super Chicken segments, but I don't think it said anything about Tom Slick being intended for that show. And while I'm at it, what's the deal with George of the Jungle being the title segment? Each half-hour only has three shorts, with George not bookening the show. They should have either made it a four-shorts show (and I think the VHS releases did include four shorts per volume, with an extra George of the Jungle short at the end of each video), or had Super Chicken and Tom Slick alternate as the middle segment.
And there's the three games that came with the NES (okay, there's a few others that were included at different points, like Mario 3 being included in 1993, and I think a ROB the Robot game was originally packaged with the NES). Super Mario Bros. is the most famous of them, with Duck Hunt still being famous but not as famous (why weren't there any sequels to Duck Hunt?). And then in the late-1980s World Class Track Meet was also included along with the other two games, and that seems to be less popular (of course, you could also say that the "clay shooting" portion of Duck Hunt is less popular).
And there's the main three Jim Henson Franchises. Muppets seems to define the company (at least before 2004, though the company hasn't done anything to match the Muppets popularity since), and Sesame Street is almost equally famous, maybe a little more than the Muppets (since Sesame Street has consistently been on the air for so long). But then Fraggle Rock seems to be limited in popularity. It could be because it was originally broadcast on HBO. But also, unlike Sesame Street and Muppets, Fraggle Rock mostly took place in its own world, so it'd be difficult to include the characters (besides Traveling Matt and Sprocket) in TV guest appearances. There were never really any Fraggle Rock movies or specials (maybe one day that movie will finally be made). Fraggle Rock always gets the least amount of focus in Henson biographies and retrospectives (to be fair, the Muppets and Sesame Street do have a lot more to talk about).
In the late-1990s, it seems like Bear in the Big Blue House replaced Fraggle Rock as that "third franchise". And it seems like Bear had slightly more going for it than Fraggle Rock did in its heyday. Maybe it helps that by the time of Bear, more households had cable (and The Disney Channel switched from premium to basic when Bear in the Big Blue House premiered), but now it seems to have been forgotten about, while every episode of Fraggle Rock is on DVD and the Fraggle characters have recently been brought back. Another thing that may or may not be a factor is that Jim Henson didn't live to be involved with Bear in the Big Blue House, and none of the classic Henson performers worked on Bear (unlike Fraggle Rock).
Then there's the original three Nicktoons. I used to think the order was Doug, Rugrats, and Ren and Stimpy, but then I read that Ren and Stimpy premiered first and Doug last. And Doug seems to be the least-popular, even though Doug was the first of the three series to be revived after the original series ended (even if Nickelodeon didn't do the new series). But it seems Ren and Stimpy was most popular at first. During the early 1990s, that show had the most merchandise as well as the most VHS releases (I know, VHS releases are merchandise, but for some Nick shows at the time, VHS releases were the only merchandise they got, and Ren and Stimpy still got more video releases than others at the time). And then Rugrats took over as the most-marketed Nick show for most of the late-1990s.
And you could say this about Lucille Ball's three most-successful shows. I Love Lucy is the most iconic of Lucille Ball's shows, while The Lucy Show seems to have been fairly popular in reruns, but I've rarely seen Here's Lucy in reruns (the only time I remember seeing that show was in a Lucille Ball marathon that aired on Nick at Nite in 1994, and I'm pretty sure Here's Lucy was never on the regular Nick at Nite or TV Land schedule). Of course there's also The Lucy Desi Comedy Hour (which was a continuation of I Love Lucy, has very few episodes, and was only broadcast on an occasional schedule) and the very unsuccessful Life with Lucy (I've read that episodes were included on the Lucille Ball marathon I just mentioned, but I have no memory of seeing that).