the recurring dream i've that wakes me up the most is falling...then hitting the ground. i credit this type of dream with helping me first attain lucidity within a sleeping dream, since i would start to notice the familiar pattern of falling through the sky, and that would sometimes give me enough time to figure out i'm dreaming...and to instead of letting myself hit the ground and wake up, to instead put a swimming pool on the ground where i was about to hit.
when i first attempted this i would still wake up when i hit the water...but i slowly realized that i just had to make the pool progressivly deeper as i hit it, depending on my veolcity...i would just keep making it deeper and deeper until i slowed down, swam to the surface, and no longer had a major issue with being startled awake by this re-ocurring dream.