Brooke Hall Hostel
17 Flodden Road - 0207 262 3507
Cheap n' nasty.
It was the cheapest hostel in London I found. You have connections to the tube (Oval station). There's a bus stop in front of the
hostel (very comfortable if you're getting back in the evenings) and you can find any kind of restaurant and market near there (including McDonalds).
The best feature about Brooke Hall is the opportunity to get a double room for just 18 quid per person/night. I couldn't find any other hostel like this.
My summary: if you plan to visit london with just a couple of bucks, this is the best hostel.