I've had one seriously disturbing dream I can remember, and one really stupid dream I can remember.
The scary one, I woke up in my bed, there were glowing red eyes in the corner of the room. This naturally freaks me out, so I go to find my parents (I was a little kid when I had this dream). In the hallway, I see a light at the bottom of the stairs. I head off down the hall, and start descending the stairs. I hear a noise behind me, like panting, so I start running, the stairs go on and on, the panting gets closer, I notice the light is no longer on downstairs, the panting thing jumps and hits my back, I fall down the stairs. At that moment I notice my family, I scream for help, they do nothing. The back door swings open, vicious dogs leap in to attack me, I scream again, but no-one helps. I wouldn't speak to my family or go downstairs for a few days after that.
The really stupid one was where I woke up and noticed I had this awful, awful haircut. It was just hideous. That was disturbing, because when I woke up, I didn't realise I'd been dreaming instantly, and thought for a bit that I did have this awful haircut. Little bit of context, all of my friends had been telling me to get a haircut, they thought my hair sucked, it was messy, etc. etc. but I maintained that it was awesome and I loved my hairstyle. I suppose it says a lot about me that I have nightmares about being wrong.
Edit: Wait, make it three dreams, I remembered another that seriously rocked me. In the dream, I was doing my daily routine, as normal, went through the actions, and at the end I was getting ready to go to bed. Just as I get into bed, something grabs me. I wake up, terrified (again, I was little at the time) and immediatly run to get my mum. Context, to get from my bedroom to theirs, you had to cross a hallway, maybe about 2 foot across. As I step out into the hallway, this creature charges down the hallway and rams me into the bookcase. I then wake up, for real this time, but I don't know it's real do I? I figure my brain my be pulling another sneaky one on me. From then on I never left my bed after having a nightmare, in case something attacked me, and to this day I regularly bite my lip to check I feel pain and am not dreaming.