Even when not using his full power, Cracker's Haki was already stronger than Doflamingo's and was able to cause Gear 4th Luffy pain, whereas Doflamingo didn't do much to him other than stall him out a fair bit. As of now, it doesn't seem as though Doffy would be able to counter the Bisc Bisc Fruit either, so Cracker definitely gets my vote.