There were tickling scenes in several of the Flintstones cartoons. Likewise, there were several in the TMNT cartoons from the late eighties and early nineties as well. I wonder if any of the writers had tickle fetishes. Of course, the fact that you see a tickle scene in a cartoon, TV show, movie, etc. doesn't mean that the person responsible has a tickle fetish. But still, when it scenes like that show up several times, you can't help but wonder.
As for favorite scenes, here's a rundown of the ones I can think of at the moment:
I'm not much of a m/m fan, but there was a scene in a Flintstones episode in which Fred was having an argument with his neighbor. The neighbor picks the fence up and drops it on Fred's legs. Fred realizes that he is in a vulnerable position to get tickled, and he says something like, "Um, ya wouldn't tickle my feet, would ya?" The neighbor tickles one foot, causing Fred to laugh like hell. Fred gets that foot free, and then the neighbor starts on the other foot. Crazy laughter continues until Fred gets both feet free. Someone has uploaded that one onto Youtube. Check it out if you want:
http://www.youtube.com/watch?v=ztR9fwF8qh4
There was also a scene in a Flintstones episode in which Fred is buried in the sand at the beach and Wilma tickles his feet. I thought someone had put this on Youtube, but I can't seem to find it.
Oh, and how about that one TMNT episode where those two guys got abducted into that UFO and tickled by aliens that looked like Elvis? That was pretty weird.
The recent Family Guy episode where Peter tickles Lois was pretty cool.
There was also a Muppet Babies cartoon where Kermit got his feet tickled by someone, though I can't remember who. Was it Miss Piggy?
The Wizard of Oz cartoon in which Dorothy was tickled as part of an interrogation.
That's all I can think of at the moment.