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?
I've given this a lot of thought but I'd love to meet oppressed historical figures. I'd love to see people autonomously standing up for themselves like at Stonewall and The Battle of Cable Street. I assume that they are both more brutal than anything I can imagine but it blows my mind to realize how many people came together.
I'd love to see the parts of town where the post-WW2 "slum clearings" took place. Gentrification is having a real impact here at the moment and its a shame. We recently lost a shabby 80s community centre and the building that replaced it never got the community back. Honestly, I just want to walk around here before the cars arrived.
A stranger thing that I would want to see is the old wood-paneled stock on the Metropolitan line of the London Underground in service at its peak. I generally would just want to explore transport systems as a whole. Getting to ride a 1910s tram on the street would probably feel surreal.
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?