There is not much "America" in American Village, but if you're interested in some really good Thai food go to the second floor of the Carnival Park shopping mall. Jai Tai offers authentic Thai cooking. There are about a half dozen set price meals, which includes soup and salad, drinks and a main entree. There are also daily specials (same as the set price meals, but without the drinks). The meals are well portioned for American appetites.
The prices are very fair--lunch for the three in my group came to just 3,250 Yen; or less than $12 per person. The staff speaks English and the menus are bi-lingual. There are plenty of seats and it looks like they have space to accomodate a large group.
All the food was really good, but for someone who likes their food hot I added plenty of chili pepper flakes. According to the restaurant's website Jai Thai is the first restaurant in Japan to win the Thai Prime Minister's Export Award. This is a place I plan to visit on a regular basis. Good food and good service at a good price.
They also have a branch at Terminal 1 at Narita Airport.