I once had a bad experience with a yellow light (actually more than one, but the others are not quite so interesting to tell about).

I was driving home from the grocery store on a Sunday afternoon. It has just rained and the roads were very slick. I was going down the road at around 30mph, when the light in front of me turned yellow. The problem was, I was at the exact distance from the light where I couldn't decide weather to floor it and zoom on through or to slam on the brakes and stop. I (stupidly) thought it over for about 3 seconds, debating what do in my mind. But by the time I was done thinking about it I was so close to the light that the only choice was to keep going, but for some reason my foot pressed the brake pedal... hard. The wheels locked, and the car slid violently as it skidded over the big white paint stripe (in the rain those are extremely slippery). I heard a horrible bending, scraping, screeching sound coming from the car as all this happened. I to this day am not sure what it was, the wheels, the brakes, or just some crap in the trunk getting knocked forward. But whatever it was it couldn't have been too bad as the car is still running fine

Anyway, the moral of the story is: if you are ever unsure of what to do at a yellow light, floor it!