Like nooo not the emo or goth stuff but i LOVE the fact that they have marvel shirts and Pokemon loot minecraft hoodies doctor who stuff and My little pony stuff i dont know where to get any other stuff like this only those to places is there a place where i can get stuff like this? I REALLY WANNA KNOW. Thanks :)

Amazon

Think Geek is a site that has loads of stuff like the things you listed.

Look on etsy for custom made things.

We Love Fine has a ton of pop culture t-shirts, especially MLP. That may interest you.

Ebay?