I'm often told my chickens' eggs have darker yolks and better flavour. I think it is more to do with what they're eating than anything, although yolk colour can vary a bit between birds and breeds. Most intensively raised chickens eat the cheapest feed they can get even if they are "free ranged", so I think that has a difference on the egg quality. If they don't get the nutrients, they can't put them into the eggs.
There seems to be some argument as to what food gives the darker yolks, some say bugs from free ranging, some say greens from free ranging, but there is still a difference between birds, even if they are all eating the same.
I'm probably spoilt. I've had my own chickens' eggs for so long I don't know the difference any more.
I have gotten to the point where I can't eat the generic, cheap eggs anymore because they just taste nasty. The free ranged ones are what I usually get.