What are some must sees in Japan

Konnichiwa,
My family and I are planing to go to Japan next year. I was woundering if anyone knows any good places to see, good food, tips, ect. Anything.
I would be very thinkful if anyone could tell something.

Domo arigato,
Geo0

The following is a good starting point for your research:
http://www.japan-guide.com/e/e623a.html

I recommend the destinations with 2 or 3 stars, in particular.

My vote is for Nikko...and Kyushu

Depends on the time of year, I think. For me the heat from (say) July to mid September is a killer,so if I was going then I'd only look at cooler places, like Nikko or Hokkaido (I havent been to Hokkaido yet, that's the trip after next). I can never get tired of Kyoto, its really convenient to get around, plenty of English spoken, and I dont think I've ever been bored. It might be a tourist trap, but they are mainly japanese tourists which doesnt kill it for me, in fact it makes it more fun. Same for Miyajima - some people rag on it, I actually liked a few days there. I think that my favourite place so far is Nara.

There is am old saying that goes " one mans meat is another ones poison"
It absolutely depends on what you find interesting.
I find Miyajima to be a major yawn yet many people rave about it. I loved Nikko but did not get the same buzz at Nara. I really enjoyed going to Koyasan but would not be remotely interested in staying overnight at a temple. I loved the Toyota museum near Nagoya but I'm not a car fanatic.
There is just so very much to see and do. You really have to research the things that look like they might interest you and go for it, Other peoples opinions are just that.

Check the travel guide that Uji suggested. I recommend going to the highest rated in Kyoto, Nara and Nikko... and there are tons to do in Tokyo.