If I'm around people I don't know, or who aren't close friends or relatives, I'm usually quite respectful and courteous, though quite quiet, I usually say please, thank you, etc. though don't hold long conversations and tend to try and get out of the conversation easily, by agreeing with them, letting them talk, etc. Though, if it's a tourist asking for directions I usually help them out.
However, with close friends or people I know well enough that I'm very confident around, I'm more of an asshole. I make somewhat offensive jokes, say things I maybe shouldn't sometimes, and usually thank people, but tag an insult at the end for the sake of it. Not to be nasty, but more for a joke. Though a lot of the time, people often take what I say to heart, so I've been slightly nicer and more honest recently. Though, I usually help my friends with problems, keep a lot of secrets for them, talk to them etc. Most people label me as someone you cannot judge until you've know me for a long time, which I guess could be said of most people. You'd be surprised by the amount of people that get the wrong impression of me though.