One of the times I laughed hardest was when I pushed the liquid soap pump in my brother's washroom. Instead of squirting into my palm, the glob shot out sideways, soared over the toilet and splatted onto the shower curtain. I laughed so full and long, tears rolled all over my cheeks.
Sometimes sarcasm makes me laugh, too, but not nearly as much. I like it when it's used in a gentle or uplifting way. For example, someone might say, "Valerie's just so selfish, spending all her evenings helping at the shelter."
I also enjoy listening to a banter between intimate, smiling friends.
Then there's an intelligent sarcasm, the kind that requires imagination and cunning. I'm envious of people with this quick wit. I wish I could come up with an example for you, but I'm not witty enough.
There's also a harsher sarcasm. The kind that sneers and ridicules. I suspect people who use it often do it so they can hide their insecurities and make themselves feel superior. It's approached with an attitude that says, "Here, let me tease the snot out of you so I can feel good about myself for a second."
I think if you grow up surrounded with that, you become numb to it, pass it off as normal, or else develop a similar form of humor yourself. As for me, it usually rubs me the wrong way because I can't see how it's edifying for anyone. In fact, many people find it hurtful.
A lot of this depends on how it's delivered, like if it's done jovially or childishly.
All I know is I'll take silly, lighthearted humor over mean-spirited, cutting remarks any day.