If you don’t thaw your turkey properly it could turn out to be a very bad thanksgiving thanks to the ever present danger of bacteria that in the right amounts can be toxic. The CDC says that the outer layer of your turkey can start growing bacteria anywhere above 40 degrees.
If you have the time the safest method to thaw is the fridge, it takes 24 hours for every 4-5lbs of turkey; for the average turkey that would mean at least 3 days.
Your next option is cold water, which only takes about 30 minutes per pound, but you need to make sure the turkey is in its own bag and not in the water–you also need to cook it immediately.
Lastly, the microwave could be your friend, for that you need to carefully follow instructions provided by the microwaves manufacturer, and again it would need to be cooked immediately afterward.