This is the best Turkey-Day gravy I have come across, and have been using it for the past few years. The stock is made the day before, but when added to the pan drippings from your T-Day turkey, it basically gives the gravy a double concentration of flavor. In fact, it's so good that I've been known to pour some in a mug and drink it like soup.
Alton Brown's Make-Ahead Thanksgiving Gravy
Alton Brown's Make-Ahead Thanksgiving Gravy