I was wondering if anyone can suggest any restaurants or where to eat in Tokyo???

Sure, I could suggest something if I felt inclined to do so.

If you're looking to try the Japanese version of American fast food, I would suggest MOS Burger. The food is reasonably priced(about 700 yen for most combo meals).

On a serious note, just go into whatever restaurant strikes your fancy. We had one of the best meals in Tokyo doing this..

I can't give you a name, but we had a delicious noodle soup breakfast from one of the perminent street vendors outside of Tsukiji Market. You bought your soup and stood at a "counter" built along the curb, to eat. It may have been that we were especially hungry or the friendliness of the vendor, but we look back on that experience as kind of a highlight.

Also, we found surprisingly good food at a good price at restaurants in the subways - a tip we learned from my brother, who lived in Tokyo for many years.

Daikokuya in Asakusa. It's more than 100 years old, very traditional, and great tempura.