According to one London book, it seems "Hampstead" and "Hampstead Heath" station are likely to be most comfortable in London.
For that reason, I visited there.
Um, I found I like more West Hampsted than these area :)
Though there is mobile shop, and nice cafe, and lake.
Hampstead: Metro Northern Line
Hampstead Heath: Overground (National Railway).
Lake in front of Hampstead Heath station.
Cafe near Hampstead Heath station
Popular crap shop near Hampstead station