I always have a tough time with the "American" quarters that you can find in the major city of Asia. It can be interesting if you're not a "Westerner" but otherwise, why would i be amazed to see McDonalds, US street wear and some clothes shops all over...not for me
Unique Suggestions: Bring your teenage kids, have a drink (or many) and read your local newspaper while the kids chat with the numerous youth of their age at the Sankaku Koen triangle park.
There is also a giant screen at that park that you could find interesting !
Fun Alternatives: There's a Europe-dori...but Europeans could say the same thing about that area...
Amerika-mura: either a tourist trap or a must see acitivity... depends on the individual, I think! I didn't like it, but I enjoyed taking some photos around there.
See my Travelogue for some Amerika-mura people pictures. Most of the kids are in their late teens, early 20's. They are trying to be... well anything but 'sweeet Japanese', I guess!