Well while these guys have a laugh at the "never been to Japan but...." post here are my thoughts.
Well Christmas in Tokyo means ILLUMINATION which is quite impressive in it's neon gawdyness. Personally it's not really my thing but it could be fun for the ohhh and ahhhh factor.
Asakusa is usually very lovely but they are doing some construction there at the moment so a large part of the temple is covered with that chalk board stuff. Can't go past Shibuya during the day or at night. Shinjuku is ok but in my opinion over rated and I don't like the area much, but that may have more to do with the fact that unless I am on the Shinjuku koen side of the station I get lost VERY easily. If you want to just walk around and think "oh my god, why am I here." then you should check out where I stayed on my last trip. Iriya near Senzoku Street (wait, was that the right spelling). It's basically been the pleasure district of Tokyo since the 17th century. But I'm not suggesting it so you can go off and get your bad thing on with hookers. The area is interesting for the small temples that are dotted all over the area. With in a 5 minute walk from my hotel there where 5 small temples and in total 7 that I know of between Iriya station and where I was staying. You could spend a day just walking the residential streets looking at all the pretty amongst the degradation of the area.
There is also a bar in Shimbashi but I can't find the card for it and can't remember the spelling. I want to kagaya or something like that. Anyway, the guy who owns and runs the place it quite possibly insane but it's a fun night of food and drink served in an 'authentic' style based on geographical locations. Lets just say, if you want your drinks served in an American style Kermit the Frog will look very different afterwards. If I remember is was like 6000 yen for all you can eat and drink.
Have fun.
