Another two I missed for the poll list - Aldi and Iceland.
Oh, the shame, the shame......
Just for the record I chose Sainsburys as well.
Nearest supermarkets to me are the aforementioned M & S food store, it's right next to the Cutty Sark boat (or what's left of it) and there's a Somerfield a short walk away, which is absolute rubbish, have to say.
Tescos are at Lewisham which is three stops away on the DLR, Sainsburys are on the Greenwich peninsula and Asdas and Lidl are at Charlton. I have to use the motor to get to those three.
Further east at Thamesmead there's a Morrisons, Iceland and Aldi all next to each other but I rarely go there.
I didn't mention Woolwich where there's a few cos it's really awkward to park there.
Although I mostly shop at Sainsburys I find that every shop has some good things that you can only buy at that shop. Asdas, for instance, has some really nice hot n spicy pepperoni whilst Somerfield has some delicious cherry ice cream.