I've never in my life had cable, so it's only because of Netflix carrying the newer Doctor Who series I've been able to discover the series last month. (Yes, I only got to start with the Ninth Doctor, but I did try to find the older series. No luck.) We're only a few seasons in, but it really is addicting.
There's just something about a character as long lived as The Doctor, Highlander's Methos or Darius or Amanda, any number of vampires, or any centuries old character. All those experiences, the knowledge, the joys, and the pain they've experienced, the things they've seen makes them fascinating. What makes The Doctor doubly so, is the writers show how he continues to grow, learning from his companions as he teaches them.
There are tons of videos out there, but I came across one that seems to sum up character of The Doctor almost perfectly.
Of course, it probably doesn't help personally that Christopher Eccleston looks like a good deal like Hubby and there are quite a few similarities between the personalities of both the ninth and tenth Doctors and Hubby's. It's like watching what he'd become if he had centuries of life ahead instead of just the few decades any of us can hope to have.