I feel like wine is a safe way to go, as long as the family doesn't have any issues with drinking (religion, alcoholism...) If you go the wine route I would suggest bringing to moderately priced bottles - 1 red and 1 white. In general either will go with thanksgiving because although turkey is light and would generally be served with a white the rest of the meal is rich and would generally be served with red. This also will solve the problem of some people only liking red or white.
There are many varieties of good red and white wines in the $10-15 range. I am partial to Australian wines and am very fond of Penfold's Shiraz and would maybe get their Pinot Grigot or Chardonnay as a white to accompany, also I am really starting to like Yellow Tail - Shiraz, merlot, and Chardonnay (and it is around $7 a bottle). The winery is also a good idea. Regardless if you go there or a wine shop the staff I've always found that the staff is always looking to suggest good moderately priced bottles.
Let us know what you decide and how it goes
