I once had a dream where I cut my left hand off from the wrist (or was it mid-arm? hmm...), using a puukko (steathknife)... Then I just, I dunno, put it back where it was supposed to be, kept it in its place for some time and it kinda molded with my arm and was all healthy again.

Also, I've had a dream where some badass snake (not in a plane) bites me and I know I'm screwed... If I remember right, that was before my high school end exams (ennen ylioppilaskirjoituksia). They turned out okay, however.
Talking about weirder dreams, I sometimes dream about absolute chaos. There is nothing but grey noise everywhere, and I of course. It's really weird a dream, it sometimes involves something I should do that I don't really understand but sometimes it fails and sometimes it succeeds... and for some reason, the whole destiny of world depends on it.
Weird thing is that I've not seen nightmares in a loong time. When I was little, I had a continuous "dream" about a snowmobile crashing into my room through the wall. Another dream involved a spaceship... I remember these dreams quite well, and I must've been under 5 years old. You see, when I was a kid we lived in a region where passenger airplanes frequently flew overheads, and particularly in the evening the lights of the planes were very fascinating to me. I knew of course what they were, but in the dream one of them turned to be a spaceship that landed onto a street. Then the dream ended usually. Strange thing, however, is that I wouldn't describe them as "nightmares", just pretty damn weird dreams. The only dreams I've been afraid in were the one involving the snow mobile, and one involving a spiral staircase and me hanging on the outside of stairs and eventually falling.