[tripa]

Here's a more neutral classic:

What is the difference between USA and USB? One connects to all of your devices and accesses the data, the other is a hardware standard.

[bryanrasmussen]

thanks, I unfortunately couldn't think of any examples even though I generally like that format of joke.

[StavrosK]

"What's the difference between a lawyer and a cockroach" or any other disliked profession/ethnic group/sex/person and animal.