Can you recommend a solid, reliable family estate car for £10,000?

Which car would you recommend as good, solid, reliable family estate that is comfortable and will go on forever? I have in mind Audi, Mercedes-Benz and BMW. I am looking at secondhand with a maximum £10,000...

Would you pick the Audi A6, BMW 5 Series or Mercedes-Benz E-Class?

I am in the very fortunate position to buy whatever car I want within reason, but realistically I am not that interested in cars other than in the need to get from A to B. Whichever car I choose needs...