I agree with khafra. If "selfish" means "pursuing things if and only if they accord with one's own values", then most people here would say that every value-pursuing agent is selfish by definition.

But, for that very reason (among other things), that definition is not a useful one. A useful definition of "selfish" is closer to "valuing oneself above all other things." And this is not universally agreed to be good around here.

I might value myself a great deal, but it's highly unlikely that I would, upon reflection, value myself over all other things. If I had to choose between destroying either myself or the entire rest of the universe (beyond the bare minimum that I need to stay alive), I would obliterate myself in an instant. I expect that most people here would make the same choice in the same situation.