This sounds silly, but I go running often, and this one time it was awesome.
It was raining heavily in the evening and was running up this last, highest crest of hills, and as I reached the top, the horizon opened up to me. A thunder-storm started raging, and the wind lashed the trees with the rain whipping down and I was sprinting over and down with this panorama of the darkened Sussex countryside being ravaged by nature opening below me.
Yeah, I suck at painting a picture, but it felt so powerful and climatic I just can't compare it to anything.