hi all, was in tokyo in late april. hope this helps you:
roppongi is slated to be the best area for pubbing. i didn't feel so though. i also felt a bit scared at night. sun set about 6 plus. rise at about 5 plus. not called land of rising sun for nothing!
these are the places i visited and really liked:
asakusa temple and the shopping around it
meiji shrine
takeshi-dori (street shops near meiji shrine)
ueno park
shibuya also got shopping but quite expensive.
for those of you who would like to watch a sumo tournament, it's very expensive (something like 10,000 yen) and you need to book like 2 months in advance.
look out for a guidebook called travelpack tokyo. it's got everything. tells you what the top 25 places are to go, tells you about each place and what subway stations are the nearest
tokyo's subway system is a tad bit confusing and certainly overwhelming at first glance. just take a minute to think it through and you'll be fine. if not, ask the station controllers - they can speak english.
it's a city of vending machines. around the central area you'll see the boring ones like drinks and cigarettes (300 yen) but i hear that in the more ulu parts, you can buy porn mags and used panties (not that i would buy, i just hear about it ok?)!