Here are some examples:
Sarcasm: Often consists of pointing out the obvious or stating the opposite. Oh, bullcrap, why tell you know what it is.
"OMGLOLRANDOM": You typically laugh at the stupid things your friends do. Often revolves around going in shopping carts through drive thrus. Personally, what I consider low-brow humor.
Racial: A Mexican and a white guy walk into a bar, get Wi-Fi access and ask for a triple mocha, post a thread on a forum and ask you what's your style of humor.
Feel free to add any in, these are just mere examples.