[quote name='Rodimus Donut']Like sleepyking posted earlier go to Akihabara. That's the otaku district. You won't need a map. You'll be overwhelmed with it all. Also if you see one head over to a "Book Off" They're everywhere. Along with books/manga they also sell used games. I've found some great deals in there.
As for arcade you must play this Gundam simulator, it'll cost you 500 yen a pop for about 8 minutes, but worth it:
But don't go halfway around to world just to buy video games. However without a guide it's kinda hard to see some of the more intresting things. Some things to do: eat real ramen, eat Yaki-niku (expensive), Visit Tokyo Tower, shrines (which can be found everywhere) if you're not to shy go to a hot spring or bath house. And since you're going at the end of March you should be in time for the Sakura, but I'm sure you know that.
EDIT - Kamakura is a historical district for some nice sight-seeing.[/QUOTE]
Akihabara is a

ing joke. I went from Yongsan in Korea to Aki and was very disappointed. I expected it to be a wet dream for a gamer such as myself. No this didn't happen. Poor selection of Old School stuff compared to what I expected.
My suggestion would be for you to buy a PC-FX. That's the Japan only sequel to the TG16. Shipping price is a bitch but buying it up close in Japan shouldn't cost you that much. It has a game called "Team Innocent" which looks quite nice and may have come out before or about the same time as RE. You also have "Battle Heat" which is an all animated fighter. Seriously pick one up dude.