Thank you guys, I got great answers, and I plan to go to the store today and try them out again, just to get a better feeling with your words in my mind. The stronger candidates to me are now Canon 30D (most likely), Nikon D80(still possible), and Pentax K10D (I need to handle it before judging it, but I'd prefer to adopt Canon or Nikon at least).
And finally I've a confession for you. I've posted the same questions in other bulletin boards, to get answers from different type of photographers and enthusiasts. Well, the best answers came from this forum. You have provided me with great answers, with a friendly and honest environment. Thank you very much. Now I wonder, should I ever pick the D80, will be there a forum like this for Nikon? 
Canon EOS XTi

