I want to buy a digital camera Canon 20D. It's this a good camera?

Highly recommended. I've only had it for a few months and have found it to be very versitile and very easy to operate. I bought after only having used a point & shoot Ricoh before and I found the basics were very easy to pick up. You'll be shooting in a variety of formats within minutes! I use it with either a 17-85mm or a 60mm 2.8 macro. It's also very good for playing back pics on the TV or PC instantly after a days outing.

If you are talking about the REALY EXPENSIVE ONE..yeah..i believe it is.
I worked with a Revel Eos and WOOOW..it's amazing...best camera i have ever seen. Depends on what you are going to use it for.

It is a very good camera. The only other in that price range I would consider is the Nikon D200. A nice review is at http://www.dpreview.com/reviews/canoneos...

DP review also has some nice user forums. Above all else, you are buying into the lens line up (Canon or Nikon). So, think about which best meets your needs and at what price point.

In terms of budget, the lenses are what can really add up. If I had to compromise, it would be on the body.