Tom Baker and Christopher Eccleston were my favorites although David Tenant grew on me as the writing improved. When I think of Doctor Who, I do think of Tom Baker first.

I think that Dr. Who is a good model for a new kind of hero, not one wed to solving problems with weapons or military excesses but one who thinks creatively, with compassion, a sense of proportion and a willingness to share a highly-developed brain for public good. I like it that he doesn't use guns.