Replying to Fun shit to do, or stores to go to downtown

Hey, I do not live in the city, but I end up travelling downtown every now and then. I usually just end up walking around and looking at stuff. And I really enjoy hanging out in the subway and such. But I never seem to have anywhere to go.

Im wondering what you guys do downtown, whats some fun stuff to do? Some cool areas to check out? or some cool stores to go to? I can never find any super interesting stores really.