Sarcasm is a big way that my friends and I find humor. I feel that my generation often communicates with one another using sarcasm. Using sarcasm and understanding it while others use it, is important for people to joke around once in a while.
You Dont Say, AHAHAHAHAHAHHAAH! I'm not a fan of this kind of humor (it think it gets annoying in real life unless everyone's in the mood), but the "You don't say" Nick Cage meme has got to be the funniest meme ever. I couldn't stop laughing.