personally i think the oyster liquor (the liquid inside the shell that the oyster is happily living in) holds a good chunk of the flavor and is the best part of slurping down a chilled oyster. but several people and/or restaurants drain out the liquor before eating/serving them. the union oyster house here in boston is famous for their oyster bar, but the way they shuck their oysters (i.e. slamming the oyster and shucking knife on a big piece of stone) causes all the delicious liquid to spill out. i'm always disappointed when i order chilled oysters and they come to me without the oyster liquor. it's just not the same.
what's your preference chowhounds?