WWJ 4 (WDIV) in Detroit didn't carry Saturday Night Live during the show's early years, and it aired on indie WKBD 50 instead. I guess the Detroit News didn't want anything to do with Lily Tomlin and a Muppet discussing sex toys.
Later. in the early '90s. WADL 38 and WGPR 62 cleared some CBS programs that WJBK 2 wouldn't run. At one point, CBS This Morning was seen on WGPR as channel 2 aired its own local "Eyewitness Morning" show.
In Toledo in the late '60s, WTOL 11 (primary CBS) and WSPD (WTVG) 13 (primary ABC) carried secondary NBC affiliations, with indie/Overmyer WDHO 24 picking up network shows not cleared by the other two. A look at the Friday night TV schedule in the summer of 1966 shows WDHO clearing the CBS network news (WTOL aired NBC's evening newscast) followed by NBC's Camp Runamuck, Hank, Sing Along with Mitch and Mr. Roberts and then CBS' rebroadcast of CBC's Wayne & Shuster. (WTOL had Wild, Wild West, Hogan's Heroes, Gomer Pyle and the Smothers Brothers from CBS and Man from U.N.C.L.E. from NBC; WSPD had exclusive ownership of ABC programs.)
As an aside, WJBK 2 didn't clear the Smothers Brothers (airing a movie in its place), and since no Detroit station picked it up, Detroit viewers would have had to try to pull in WTOL or Lansing's WJIM 6 to see it. Frankly, I'm surprised WJIM cleared it at all given its ultra-conservative ownership at that time.