i voted for the wilderness lodge which is very romantic with the large lobby fireplace, but my favorite resort at christmas is the boardwalk inn which has some great xmas decor & exhibits like xmas villages made of chocolate & beautiful christmas trees. i also love all the entertainment on the boardwalk, how close epcot is, we head to world showcase every night and we love to come back at night and stroll the boardwalk, path & beach club beach across the way.
they also have specialty cruises from the yacht club across the way, which you can request a pick up at bwi, we did this for a romantic evening on a pontoon for an illuminations firework cruise which we just loved! we also did the breathless moonlite cruise at the yacht club which was just as enchanting.
you can book either through 407-wdw-play
have a wonderful wdw anniversary trip! congrats on your years together!