I have a theory, the current doctor when you started watching is your favorite doctor. Would this apply to you?
I started watching Dr who when the reboot was 3 seasons in, I think David Tennant was the greatest doctor. A few years later I finally got wife to give it a shot as I started a fresh rewatch in preparation for Matt Smith's second season, she was ok with Eccelston and Tennant but Matt Smith is far and away her favorite doctor. Does this pattern hold true for any other Dr fans?
A lot do love their first Doctor. I'm old school and started watching as a tiny kid and it was Jon Pertwee. I love Tom Baker but Peter Davison became Doctor right when my teen hormones hit so he's my favourite Classic Doctor! Peter Capaldi is my favourite Nu Who Doctor.