Microsoft accepts Bitcoin. You can "redeem" Bitcoin on your Microsoft account and make purchases through the online Microsoft store. They are the Biggest retailer that I know of that accepts Bitcoin. Other large retailers are Newegg and Overstock. In Japan, Bic Camera is a large retailer and you can use Bitcoin to purchase items in all of their stores. That was pretty cool. These are huge legitimate businesses.
I once tried with Newegg but what i can see is that not everything can actually be bought with Bitcoins. In this instance, I was trying to buy a PSN code to buy some games for my PS4 but when i got to the payment side i couldn't see bitcoins.