Today I find a physics meme: spherical cow
Q: How does a physicist milk a cow?
A: Well, first let us consider a spherical cow...
With the notorious Schrodinger's cat, I think a list of meme in physics would be fun. What do you think?
Maybe not a list of memes, but somewhat on related lines was this (now closed) question:
(Actually, there also a deleted question - https://physics.stackexchange.com/questions/70740/do-good-physics-jokes-exist, which was also removed for the reasons of moderation.)
If you scroll through the existing comments on the linked page, you can appreciate the reasons why it got closed. Still for reasons of completeness, apart from DavidZ's answer above, it makes sense to reiterate dmckee's point in the original thread:
There is no format in which you can ask this question. First, the Stack Exchange engine has been carefully built and tuned to deal well with question that have right and wrong answers; and it does not mange lists well. Second, while these kinds of questions are enormously popular that very popularity makes them destructive to the question & answer environment that is what we seek here: "best this" and "favorite that" question push out the substantial content. It took more than two years for a majority of the active users on Stack Overflow to understand this, so we learned the hard way.
Thus, long story cut short - even though most people would really like that question and the answers, SE sites are not the appropriate place for such big list questions. Sorry :(