As a Brit, it is interesting to note that there is not that much united about the United States. I'm guessing you guys must think long and hard about moves to certain states, depending on your personal tastes and stuff...
The laws really aren't so different between the states that it makes a huge difference. In determining your ideal place to live, like for retirement or something, you might consider a couple of specifics that apply to you; dope, gay marriage, gun regs, etc. And taken as a whole, you will definitely consider some states to just be more your type of atmosphere. I'd certainly get along better in Oregon than I would Arizona. Overall, though, there are far greater concerns. I wouldn't turn down a great job in Arizona because they're all a bunch of nutjobs, for example.
And as it applies to my situation, I've been a pothead going on 30 years. The fact that it's illegal here hasn't really been a huge concern. I find it silly and annoying that I have to be so cautious, but the risks aren't so great that it really troubles me too much. While a state that's actually civilized with regard to such matters would certainly look better to me in a totality of circustances sort of way, I wouldn't pick a state to live in because of their pot stance. The same would apply if I were a homo or a gun nut.
Honestly, terrain and weather would trump almost all social regards for me.