Red Ken has sorted out the busses rather well IMHO so that provided one is able to avoid knife-wielding gutter punk kids throwing chips at their girlfriends, busses are a real transportation option these days. The Tube and the public-private partnership is its usual crappy self. I am a keen cyclist and enjoyed cycling when living about an hour out of Kings Cross, but even I shy away from doing so in town. Maybe I would consider it if I had a David Cameron-sized entourage to run interference, but sadly I just don't think London's made for pushbikes. Motorcycles, maybe, but that's too crazy for my blood.

If I were to own a car in London I would definitely go for a used Honda Civic, the ones built in Swindon since I guess 2005 or so. Very sexy for a Honda, great mileage and low emissions with the diesel engine and tough enough for the inevitable urban bumps and scrapes, but really when the CC and petrol and parking is factored in.... bah.