I’m coming to the end of Downton Abbey, and so I’m looking for the next English (or, pretend English) show to watch. I’ve been hearing and seeing a lot about this Doctor Who, and judging by his name I assume that he’s supposed to remain a mystery. However, I am curious and I want to know who’s Who, what’s what and why. With several seasons in existence, from however way back when, I don’t know whether or where I should start. This short note therefore is basically a plea for advice. Is Doctor Who worth watching? If so, where should I start? If not, what else and why? Thanks!
Happenings 
I’d say there are two ways to tackle this:
If you want to watch all of the 2005-current show, there are only 7 seasons and some change so starting at series 1 might be a good place to start, although that first season is “hit or miss” for the first few episodes.
I’d almost recommend starting with series 5 (Matt Smith’s first season) then going back if you enjoy it. It’s not that they are far superior or anything, but the show slowly teaches you history of the whole show pretty fast, and those eps are in HD etc.
Many thanks for the guidance!!