I don't always wear my seatbelt. I do when I remember it, which is 90% of the time, but if I get in a strange car, sometimes I forget. I do find it more comfortable without, but people get mad if I don't buckle up in their cars, typically. I'd rather not fight about it.
And when I drive the work van ... I shit you not: the belt is more to keep me in my seat than it is to save my life in the event of a crash. I drive that van hard.