Hint: it ain't built in Seattle.
Hate to be picky but B737-800's are built in Witchita (& Boeing's HQ is in Chicago).
Of course you are comparing the worst Boeing single aisle type against a much newer Airbus wide-body type. I've said for a long time that the A320 is a far superior aircraft to the B737 (all variants) but as far as widebody's go, I believe that the Boeing product is way ahead of Airbus.