I always say "you are so good looking!"
Besides, who the hell is arrogant enough to think they have the power to bless me?
My DH and I loved Seinfeld - he says that to me when I sneeze. Makes me smile every time. You should see the looks he gets when he says that in front of someone who doesn't know where it comes from.
The person saying "Bless you" isn't blessing you...society has become so politically correct that we've droped the God part of "God bless you" - so, originally it was God who was blessing you. So without God in there anymore I believe, if I can remember back to English class, that what we are now really saying is You bless you. For those of you who do not believe in God I am not making a judgement...you can believe in whoever/whatever you choose. I'm just making a comment on the evolution of the saying.
As we must account for every idle word, so must we account for every idle silence." ~Benjamin Franklin