mwagher7700 beat me to it. Another tradition in our family was a good shrimp cocktail. Go extremely low on quantities, though. This is the case where the dish really needs to serve the purpose of appetizer. Just enough to whet the appetite. You'll know you did right if people are looking for appetizers and you've run out! Seems unusual for a good hostess or guest to run out of anything, but for Thanksgiving, the meal is indeed the deal!
And if you haven't tried the tidbits, they are a real hit!!