
Mo-Mo-Paradise (shabu-shabu)
I am not a great meat fan, I am not a Japanese cuisine fan and I am not a Shabu Shabu or Sukiyaki fan. However, I am aware that many of you out there like it so I might as well tell you about Mo Mo Paradise ("Mo Mo" stands for the mooing of a cow, source of the meat you will eat), which is cheap, ubiquitous and fairly good.
At Mo Mo Paradise, part of the chain which owns Fujimama and Barbacoa, the deal is simple: 1500 yen for all the Sukiyaki OR Shabu Shabu OR both you can eat for two hours. There is an all you can drink set including sake, cocktails, wine and soft drinks for 1200. Do not expect much in terms of atmosphere. As I am sure you realize, at an all-you-can-eat restaurant, that's not the attraction.
Web : www.wondertable.com/app/tenpo/tenpo?code=MoMoParadise
(with the list of the 9 restaurants in Tokyo)

En (izakaya)
En" is part of a chain of 13 branches in Tokyo and the Kanto area, although you would think it is a carefully managed single entity. Distinctly upmarket when compared to most "izakaya," it offers finely prepared Japanese food and attentive but never obtrusive service in a quiet, comfortable atmosphere. The Takadanobaba branch features all "horikotatsu" seating, meaning that you sit on cushions at a low table while dangling your legs into a pit below the table. Decidedly more comfortable for the gaijin (and, I'm told, for most Japanese) than sitting on tatami.
There are several private rooms, too, apparently without an extra charge. We were a group of four non-Japanese and were shown into one of these private rooms by the young but polite and knowledgeable staff. The main menu is in Japanese, but they do provide a shorter version in English.
The food is upmarket "izakaya" fare but often with a twist. An avocado salad with distinctly Japanese looks and flavors. The grilled "tsukune" minced chicken not on the usual skewer but in a shape reminiscent of a frankfurter and not, for a change, overgrilled. Cabbage leaves with six different kinds of home-make "miso." A large variety of seasonal sashimi and grilled fish and clams. In my estimate, the menu lists over sixty or seventy items, and the one vegetarian in our group found plenty to choose from, too.
We didn't try their wines, instead stuck to beer and sake. Naturally, there's also a variety of "shochu" and "shochu sours" made with freshly squeezed juices.
After three hours of eating and drinking, the total bill for four came to not quite Yen 25,000 or a little over 6,000 per head. Perhaps slightly more than at your normal student-type izakaya, but distinctly cheap when you wish to impress foreign visitors of either sex. (The ease of "playing footsie" can be a welcome side benefit of the "horikotatsu" seating arrangement.)
Other branches of "En" are located in Ikebukuro (2), Shibuya, Shinjuku, Jiyugaoka, Ginza, Kichijoji, Kawasaki, Yokohama, Omiya and Tokorozawa.
Web - www.izakaya-en.com (about 15 branches around Tokyo, plus some in Kansai)