We stayed for a weekend at Sean and Sally's house in Southfields, London. It is a beautiful art-filled house and a lovely, clean and airy room next to a private bathroom.
You're about 10 minutes walk away from the station and only about 30 minutes into central London but you also have Wimbledon Park right behind the garden.
The district line train line does run at the end of the garden but it doesn't run at night and we hardly heard it at all.
The house is very clean and Sean and Sally are excellent hosts - they know everything about London and gave us great advice about what to do and where to go. Highly recommended!