When I was growing up I heard the title Doctor Who, maybe once or twice. I had no idea what it was was about. My older sister said that she used to watch him but she couldn't recall which doctor.
The first time I ever saw a Doctor Who episode was about three years ago and the Doctor was Christopher Eccleston. I think I saw the second episode of the new season one. It came on public television about midnight and so happens I was channel surfing.
By the end of the first season I was hooked. The way they ended season one was very powerful. (for a tv program)
Tom Baker was very good, but I think Peter Davison got more emotionally evolved and seem to have more regards towards human life.
I remember an episode where Tom had given a seemingly doomed man a weapon, who then preceded to shoot himself. But I remember one, while Peter Davison was there, where he nearly started crying because his enemies were dying. Now thats a Doctor!
Anyway, I like them all. The one thing that appeals to me the most about the Doctor character is that he refuses to except the inevitable, and often changes it. There's always a happy ending to an impossible situation.
That is also the reason why I detest Tourchwood. Captian Jack compromises to much and I'm usually feeling uncomfortable when they end the show... but to him his own.