I voted, but it was really hard to pick a favorite.
When I was younger, my favorite Doctor was definitely Tom Baker, and my favorite companion was Elizabeth Sladen as Sarah Jane Smith. She wasn't my first companion though. That was Lala Ward as Romana.
When our PBS station stopped cycling through the Tom Baker years after several year, they started play the other early Doctors, William Hartnell, Patrick Troughton, Jon Pertwee, Peter Davidson, Colin Baker, and Sylvester McCoy. the episode before Tom Baker was a treat. It was a nice time in my life.
When I was older, and Doctor Who was revived, it became impossible for me to have a favorite. The current doctor was always my favorite.