Congratulations on 20 years! We have been making Thanksgiving trips every year now since 2005, and we celebrated our 20th anniversary in 2005 on the day before Thanksgiving with dinner at the California Grill at the Contemporary, After dinner you can watch Wishes from the roof of the restaraunt (don't know exactly what they call this area, it's not really the "roof", but you know what I mean). They pipe the music into this area for viewing. You could also get a table inside that would allow you to watch the fireworks from inside.
We make a Thanksgiving trip every year, and we always schedule our anniversary dinner for the California Grill. Great food, atmosphere (view!), service, and desserts. Make sure wherever you go that you tell them it's your anniversary. Our dessert arrived with beautiful Happy Anniversary wishes written in gold foil on it!
If you have time to kill between dinner and the fireworks, you can just ride the monorail around and come back to the Contemporary. It's fun at night! They let you back into the restaraunt for fireworks as long as you have your dinner receipt.....
Note #1: We also have a tradition of having Thanksgiving dinner at the Brown Derby at MGM. Great atmosphere and food. After dinner, we walk through the Osborne lights with the fake snow. The dancing lights last year were terrific!
Note #2: We also do this with 3 kids in tow. The teens love good food and there's a great kids menu for the 6 year old. A bit pricey, but we don't tend to overdo the food most of the time.