If you're going to the trouble of cooking turkey for Thanksgiving, you simply must make your own gravy. There's simply no comparison between home-made gravy and store bought; it's worth the trouble. Here's a recipe modified somewhat from the November 2002 issue of Sunset:
Giblets, neck, and liver from turkey
2 onions, peeled and quarters
2 carrots, peeled and cut into 1-inch chunks
3/4 cup celery
approx. 2 quarts broth
1/2 cup corn or potato starch
Salt and pepper to taste
Chill liver to add later. Put giblets, neck, onion, carrots, celery, and 1 cup water in 6 qt. pot. Bring to boil; reduce heat and simmer 15 minutes. Uncover and stir over high heat until liquid evaporates and contents are browned and begin to stick (15-20 minutes).
Add 1 qt. broth and pepper; stir to free brown bits. cover, reduce heat, and simmer, stirring occasionally, until gizzard is tender (1 to 1.5 hours). Add liver; cook 10 minutes longer.
Strain mixture into a bowl. Remove the meat from the neck and chop the meat, giblets, and liver. Discard the bones and vegetables. Measure stock and add broth to make 1 quart. Combine everything into unwashed pot.
When turkey is done, remove rack and bird; skim fat from drippings. Add 2 cups broth to roasting pan and stir over low heat, scraping brown bits free. Strain mixture into pot with stock and bring to a boil.
In small bowl, blend starch and 1/2 cup water. Add to stock and mix until boiling, 3-5 minutes.