I know I've read a number of economists doing utilitarian analyses of drug legalization that take into account the enjoyment people get from drugs. Jacob Sullum's "Saying Yes" is basically a defense of drug use.

I argue in favor of keeping your damn dirty hands off my fatty food on the basis of my enjoyment of it. I also enjoy rock'n'roll, but don't care much about sex'n'drugs (though I think those should be legal too).