trocadero if u want to play Mario kart, f-zero ax etc etc.
Park lane and pop into the aston martin shop.
If you are after strange buildings to see, then you cant go wrong and take a gander and the giant massive erect cock
errr. Picadildo circus is a great place, lots of shops and other crap. Oxford street for the same reason. You can always go to hackney and experience what it would be like to live in garbage.