Slightly biased as this is where I live, but Stoke Newington is great place to spend lazy saturday / sunday afternoons getting sloshed with friends. There are 10 + pubs within walking distance who all are great places for one reason or another. I'll pick out the White Hart for its huge beer garden...
It is a music store in Brick Lane. You can spend there the perfect Sunday afternoon, listening to lot of new good music, thumbing through cool books while relaxing in their café. Oh, and the Rough trade photo-booth is a must if you go there!