HBO. You love their ground breaking documentaries and award winning movies, now you can enjoy all the fan gear from their HBO Store . And for less, we might add. Just apply coupon code DAD20 to save 20% off all purchases in honor of Father's Day. Maybe your dad would enjoy a new t-shirt, mug, or DVDs from such shows as True Blood, Game of Thrones, Entourage, or Curb Your Enthusiasm. Alternately, code HBOCOUPONS5 will shave $5 off orders of $50 or more. Coupon's expirations are unknown, shop soon.