I'm up in Misawa (3.5 hour train from Tokyo). Been to Tokyo a half dozen times or more. If you happen to be a veteran, the New Sanno Hotel is cheap and very nice.
I recommend Gonpachi, aka the "Kill Bill" restaurant (the place that Tarantino based his Japanese restaurant off of for the "Crazy 88" scene in Kill Bill). It's cool if you're a fan of the film, and the food was actually very good.
For night scenery, Shibuya Crossing is awesome, as is Shinjiku. Or if you're near the Kill Bill restaurant, Roppongi Hills is just up the street and a nice glimpse of modern yuppie Tokyo (an artsy courtyard with a great view, and skyscraper apartment buildings with malls on the first floor).
During the day, the big temple downtown is a cool cultural thing to visit, if you want there is a cool river boat that goes from a downtown park and drops off at the temple (activity plus transportation in one!). And of course there is Tokyo Tower (it's actually a really cool view from up there).
Basically, if you're prepared to pay ridiculous amounts of money for everything and don't mind mega-citiies, Tokyo can be fun. But if you find New York too busy and are on a tight budget, you might hate Tokyo, lol.