An Izakaya is a Japanese style bar. When you hear that Japanese businessmen go
out drinking every night an Izakaya is were they go. I don't have much experience
with bars in the U.S. but so far I really like Izakayas. They have all kinds of food
and they serve it in small usually pretty cheap portions so you can try lots of different
things.
On of my favorites is Tsubohachi which is a very large chain. I think there is a
Tsubohachi Izakaya near practially every train station. There's one near my station and
one at the next station. There are two or three of them in Shinjuku. My friend
Mark first took me to the one in Akasaka which is kind of the business district of Tokyo.
He says it's not a good one but then I like it because it seems to have a little
more variety of food them many. Here's the menu.

I suggest you click on the picture and scroll around the big version of this picture.
Warning. It's a BIG file. About 1.5meg. But on the big version
you can see all the different kinds of food and the prices. The prices are in yen
and one yen is about equal to 1 penny so if it says 300yen that's 300 cents or 3 dollars.

This is the drink menu at Tsubohachi. Izakayas are usually very loud places and
you can often hear people playing drinking games with their co-workers.
I think most Izakayas are similar but they all have different menus and specialize in
different things.
So far the best one I've been to is the one at the Nikko Hotel in Kawasaki. You
can read about it here (Random Stuff)