This is not for the shows that did change networks, nor is it for shows you wanted on another station but wasn't ever planned to happen. For sitcoms, dramas, and dramedies, no reality or game shows.

Full House- WB would have moved this to their station from ABC. But John Stamos thought the WB was beneath him and would have quit, Stamos was too important to the show for it to continue without him.

This is not for the shows that did change networks, nor is it for shows you wanted on another station but wasn't ever planned to happen. For sitcoms, dramas, and dramedies, no reality or game shows.

Full House- WB would have moved this to their station from ABC. But John Stamos thought the WB was beneath him and would have quit, Stamos was too important to the show for it to continue without him.

I can think of one show that fits the criteria you set, Batman. Now whether this is true or not is another matter (which I'll get to). Adam West claimed NBC inquired about the series after ABC passed on a 4th season, but the sets had already been deconstructed so they ultimately passed. Adam West and Burt Ward told a few Whoppers in their time so there's that... . The only reason I put this one out there is it has a small degree of plausibility.

Get Smart's ratings had been trending downward and there was a slot opened on Saturday night that was ultimately filled with The Ghost and Mrs. Muir which was coupled with Get Smart as the back half of the 8pm-9m slot on Saturday night. The coupling of the spy parody with a super hero parody might have been a better fit and helped both shows. Adam 12 was the 7:30 show, NBC could have scheduled Batman for 8:00 pm and leave Get Smart at 8:30 (its timeslot at the time) or switched them. The Ghost and Mrs. Muir a family friendly show was just starting out, and it would be pitted against the long running family hit My Three Sons, and the still popular with the older folks Lawrence Welk Show. From a counter programming standpoint it makes sense.

On the other hand Batman was a flash in the pan, it had a big half during the first 6 months of 1966. When the show returned in the autumn of 66 it went into a freefall and was almost cancelled completely at the end of season 2. As it was the number of episodes were cut in half but the show continued to falter in season 3 with ABC finally giving up on it. Why then would NBC sign up for a show that had been a fad over a year earlier.