Many shows, live action and animated, have done it, and quite frankly, it gets annoying a lot. "WE" are not supposed to exist, "WE" are supposed to watch them and pretend they exist, not the other way around. When they do it to us, it does not become funny, it becomes annoying.
Live action examples:
"The Golden Girls"
"Malcolm in the Middle"
"Wizards of Waverly Place"
"Sesame Street" (and movies)
"The Muppet Show" (and movies)
Animated examples:
"Garfield and Friends"
"Family Guy" (a lot)
"American Dad" (a lot)
"The Simpsons"
"Spongebob Squarepants"
"Rocky & Bullwinkle"
"The Flintstones"
"Tiny Toon Adventures" (I think)
"Ed, Edd and Eddy" ("Kevin was not even in this episode, Eddy")
I was watching "the Grim Adventures of Bill and Mandy" today, and Mandy replied to something with this comment, "what a waste of an episode"; in the same episode, if I remember correctly, a machine strangled a caveman who is supposed to be Fred Flintstone, and took out his brain, he then grumbled at the camera, come on. I know it is fiction, but it is supposed to be reality, and we are supposed to be unidentifiable.
I cannot think of so many more, but you can find a lot if you search on-line. If you visit the IMDB, you can go to the search section at the bottom left, and then go to the word search section, and make sure you put in "breaking-the-fourth-wall" as written, it will not work any other way.
Anyway, I hope this helps. I will let you know if anything else comes to me.
Looneytunes/Disneytoons