One time over the phone my eldest brother - who, I might add, is a crown prosecutor and very PC and VERY tender-hearted - told me the most appallingly un-PC joke I have ever heard in my life, and he had to hang up because I was laughing so hard for so long I couldn't speak. I would never be able to repeat it but oh, it was GOOD!!!
I rarely laugh at jokes and people are always like "You don't think that's funny?",,, And I'm like, no, I really DO think it's pretty funny, but not many jokes make me laugh, but really good ones can be pleasantly surprising.
I voted "sometimes", though "rarely" might have been a better choice. My usual reaction to a joke is to smile or shake my head. I really tend to laugh more when somebody makes a very dry, off-the-cuff remark.
I had to leave a classroom last week, though, and laughed till I cried, when a very shy, sweet student unintentionally came up with a very obscene expression while translating aloud in class. It was better than any joke!
I laugh usually unless its something grosss, like the dead baby jokes or something. I am a terrible joke teller, but am often funny if I don't think about it and just say something. My favorite joke happens to be really offensive though, so I hardly ever tell anybody.