I will have half a day to spend in Berlin, on a Saturday afternoon. What do you recommend I should go and see/taste? I am not aiming for classical "tourist" spots, as we have a guided city tour before, hopefully it will show all the interesting spots, but much more the the things that are not so obviously on the must see and do, but they are still interesting.

I am interested in going to an antique shop or two, to a food shop (where i can buy Lebkuchen and good German sausages) and I really enjoy the hidden architecture gems of old houses. Nothing new, nothing fancy, nothing modern. I'd like to skip the museums and galleries, I have the tendency to spend in there too much time, which I don't have with this occasion.

Also, can someone recommend a Toy store in the area around the Tiergarten?