Off the top of my head, SpongeBob SquarePants, Danny Phantom, Fairly Oddparents, The Big Bang Theory and It's Always Sunny in Philadelphia all have jokes, if not the main plot point of the episode, that are just mocking the existence of LGBTQ people.
deleted by creator
I distinctly remember media here being upset about the clam episode PROMOTING homosexuality.
Even with the first two you mentioned, I don't think the joke was that something that was gender non-conforming or homosexual was done.
Mr. Krabs gave a disingenuous response to SpongeBob asking if he looked pretty, and the mail deliverer gave him a look of disrespect for doing that, while SpongeBob and Patrick raising the clam as the mother and father is portrayed as being a bad thing.