I was recently reminded, due to World War I, of some poems I wrote last year after being inspired by a WWI book that I read. I was inspired, I think, by the utter uselessness of that conflict in tactical or strategic terms, and felt very sad, angry, and despairing that we live in a world where such an outrage could happen.

So I decided to do something to pay homage to the people who fought and died in WWI. An hour or so later, I found that I'd written a series of ten short poems dedicated to the men who fought and died in the two World Wars (with the poems based on actual incidents from the World Wars) and told to us through the eyes of a fictional corporal in the British Army. Although I've been writing both prose and poetry for 14 years, it was the saddest thing I've ever written.
Anyway, that's the background to my question. So my question is... which do you think is the most powerful emotion? We in the west are constantly being told that we should be happy and that the way to be happy is to buy stuff. I don't have too much of a problem with being happy, but I constantly find that when I'm sad or angry I write much deeper or more insightful poetry. Are despair or rage more powerful emotions than happiness? I know that when people are enraged, they sometimes do things that they wouldn't do otherwise, but... it doesn't seem, well, "natural" to me to be angry. *puzzled*
Thoughts?