As a European (and particularly, as a Brit) I tend to look at most of our 'explorers' as violent colonisers, and consequently have complex (but mostly negative) feelings towards them. It also seems that's the way the public opinion here is moving (at least in my microcosm).
Is that the same in the US? I understand it may be a little different, in that Columbus is so tied into the grand mythos of the creation of the US.