I've had some really good ones.
In one, I was lured back inside my old school by a girl I'd always wanted, but who was never interested in me when I went there. But when I got inside she was gone. I tried to find her, since, well, she was WAY ready, if you know what I mean, before I followed her inside. But as I explored, I found myself lost. There were all these twists and turns and halls and boiler rooms that were never there in the first place, and I kept hearing voices but couldn't find anyone else. Then I realized: I followed her into my old school, but the school wasn't where it was supposed to be. It was blocks away from its real location. Whatever I was inside was alive, and now was changing its shape to keep me there, toying with me, and there was no way out. I never escape, just eventually wake up.
I've had the classic "falling" dream. But once, I realized it was a dream and the panic left. I was like, "Yeah, I'll wake up before I hit the ground." Then I hit the ground, and heard a sharp crack. And I realized that I could see my own back; my neck had broken and my head was twisted around the wrong way. And there was blood EVERYWHERE. And I thought, "Oh God, this wasn't a dream, I'm about to die." Then I wake up.
One rather unconventional dream had me going out my front door up to buy some dinner for myself, when I suddenly noticed that the clouds in the sky were gone, and it was just a clear blue, the exact blue you might get if a TV isn't getting any input on that setting. Then the trees were gone. Then the houses and the ground. And I was floating in a blue void as a booming otherworldly voice announced that the world had ended, glory to Allah. Being a Christian, I remember thinking the exact words "Well, I'm fucked," in the depressed acceptance that even though I was most likely damned, at least whichever God was actually real was taking care of business now. Then I woke up.
Those are my real nightmares, and the trapped in a living malevolent structure one reoccurs, though the circumstances change from time to time. But on the whole my dreams are usually really nice, and I'm usually more annoyed to wake up than relieved.