This happens to me so much that I feel like one of the loading hints should be "Not Tipping Over..."
My current game is hard mode (no save/revert) with life support, so this sort of thing is catastrophic, especially when it happens on a manned mission in another planetary system. So here is what I do to prevent it:
1) Use Kerbal Engineer to see the slope of the place where you are going to land. If it is outside of the tolerance of your lander (you did extensive testing, right?), then abort the landing and power up the ascent engines.
2) Bring along a rescue system. I use an ascent vehicle based on a command chair (since it is just for emergency/backup use anyway) that can descend to the surface, pick up the kerbal, and return her to the main vessel. The extra mass on an interplanetary mission is not too bad, considering that you can leave it there.
3) If I have to land in a place with a large slope, I send a probe first to scout out a good location.
Overall, I agree about Mun, though. It's not worth the risk after the first contracts and science grabs.