What's your favourite Doctor Who "era"... marked by who was the producer/showrunner at the time...
Mine has to be Phillip Hinchcliffe. I love the macabre nature of his era.

Although the first Who I saw was the Russell T. Davies era, my all time favorite it the Barry Letts era, followed by the Hinchcliffe era.
I voted for Verity Lambert.
Without her there'd be no other eras at all. The imagination and atmosphere those guys communicated on budgets and schedules that would give current TV people a breakdown was nothing less than remarkable. They left a massive impression on modern culture as everyone knows. They invented the man in the box and the deadly pepper shakers.
Barry Letts and Phillip Hinchcliffe both come in at a close second.

Most definitely Phillip Hinchcliffe. Pretty much everything was right about his time in charge.

The Russell T. Davies era, without a shadow of a doubt.
It was the first era I saw, and it was that era that made me fall in love with the show.