Two, one I haven't had for a while where I'm being chased by something, finally think I've got away and then it rears up in the rearview mirror or back seat of the car I'm escaping in.
One I still get is that I have an exam but I haven't studied and am panicking about it, usually it's something like an important end of year exam and something impossible to catch up for (like a language exam, I used to study languages). I don't ever seem to get to the exam, actually maybe once I can remember, mainly the panic and feelings of letting myself and others down.