Assume you have all the luxuries of a modern life in your Tardis (toilet, hot showers, TV, books, game console, ...) which doubles as a mini self-sufficient apartment with it's own energy stores and generation.
Where in history would you go if comfort wasn't an issue?
Oh WW2 London is a fave of mine. I've always wondered what the slums of Deptford looked like. Right now it's an overly gentrified rich person's suburbia, but back then it was the rotted lungs of the shipping industry. It would be also nice to know what it was like hiding out in the tube with a bunch of strangers. Did anyone play music? Was there singing above the praying? Did people trade books and cigarettes?