But Looney Tunes was the most ubiquitous. I swear each channel had their own package, be it named Looney Tunes, Merrie Melodies, and various LT character names. And I'm sure a lot of it had to do with a lot of the LT shorts being public domain.
Only 123 Looney Tunes/Merrie Melodies are in the public domain, which is still a lot, but I don't remember knowing of any stations that ran their own Looney Tunes shows comprised entirely of public domain shorts. Maybe there were some and I just don't know it.
But Warner Bros. also separated the cartoons it owned the rights to into three separate television packages, though the packages did swap cartoons every few years (Nickelodeon promoted this fact in 1992). The "Looney Tunes on TV" page at Jon Cooke's old Looney Tunes site on the Golden Age Cartoons website (which now redirects to the Golden Age Cartoons Facebook page, though the pages were saved for internet archive) talked a bit about it, saying that there was a package of the most popular shorts, a package of some well-regarded shorts, and a package of everything else (practically what the networks did not want to touch). But considering they swapped cartoons every few years, the packages wouldn't completely be that. I know that in the late-1990s, Kids WB aired a lot of the really well-known cartoons, like Duck Amuck, One Froggy Evening, The Rabbit of Seville, and Duck Dodgers, but Nickelodeon also aired some of the best-known ones, including What's Opera, Doc?, Duck! Rabbit! Duck!, The Hasty Hare, and Porky in Wackyland.
When Nickelodeon started airing Looney Tunes, they mostly got all the cartoons that weren't on other stations. Various black and white cartoons, including Bosko and Buddy,redrawn colorized Porky Pig cartoons (though I don't know why other networks would have been against those, they may be badly redrawn but wasn;t the point to get those old shorts television exposure?), many post-1964 cartoons (the ones that don't star Speedy Gonzales, Daffy Duck, or Road Runner) were broadcast for the first time, Nickelodeon never seemed to have a problem with airing Speedy cartoons (and this was when ABC started airing Looney Tunes and refused to air anything with Speedy), and the channel got a number of politically incorrect cartoons that would have probably been rare sooner otherwise (though there were also a lot of politically incorrect cartoons in Nick's package that didn't air on the channel). It's amazing that the channel got the rights to some of the cartoons made between 1948 and 1964, I'm not exactly sure how small that selection was. But when cartoons swapped in 1992, Nickelodeon started airing more of the better-known pre-1964 cartoons and dropped the Bosko, Buddy, Beans, and early Merrie Melodies cartoons (and started to phase out black and white Porky and Daffy cartoons, though they still continued to air for a few more years).
I think Nickelodeon might actually have helped make the Looney Tunes popular in the 1990s. Looney Tunes came to the channel around the time that Nickelodeon was starting to become a really popular cable channel. I had seen Looney Tunes before seeing Nickelodeon, mainly the syndicated Merrie Melodies Starring Bugs Bunny and Friends and some public domain videos, but Nickelodeon's airings was the first time I really remember seeing Road Runner, Wile E. Coyote, Speedy Gonzales, and Pepe le Pew (though I do remember that Road Runner cartoons were frequent on Merrie Melodies so I don't know why seeing one on Nick was the first time I remember seeing one, maybe I actually saw Looney Tunes on Nickelodeon before Merrie Melodies).