What should we do in Tokyo?

I will be in Tokyo for 3 days and 4 nights. I just dont have a good idea of what to do in the city. We will probably see all of the tourist events. Please let me know of any great suggestions or fun ideas.
Many thanks in advance.

Some suggestions:
http://www.japan-guide.com/e/e2164.html

It depends when you stay in Tokyo.

When I stayed in Tokyo, I used a volunteer guide service. The guide helped me a lot.

Tokyo Free Guide
http://www.tokyofreeguide.com/index.php?ml_lang=en

I recommend go to Kamakura (1 hr from Tokyo)where is peaceful and very nice town ^^
Enjoy your trip!!

Did you thought about looking at the sections at the very top OF THIS SITE, like A-Z, that are a gold mine of info? how about looking also at guide books and googling "Tokyo tourism info" etc. or even looking at older pages in this forum. Each person has different tastes and your idea of fun things to do is likely not mine and vice versa yet we are both right. Once you give us an idea of things you might like to see and do, based on your research, then we can give you a better feedback.

...that you go and see the "Meiji-Jingu shrine" (Harajuku or Yoyogi station) - it's a really beautiful shrine located in a peaceful area.

And why not go and check out Ginza if you're into shopping, there are loads of good restaurants in the area too.

If you interested in Japanese gardens i can Recommend Shinjuku Gyoen, which has a specially dedicated japanese "area" or Hama Rikyu.

There is A LOT to see in Tokyo, the only question is, what you choose to see in your fairly limited amount of time there.
Your choice may depend on where you are staying, as Tokyo is a huge city that isnt always easy to navigate if its your first time there.