Thanks for the correction, did not know that

(English is not my strong subject

)
Hi Morozov,
I think if you intent to have a single all purposes len
s to go with your camera than 18-200mm len
s is the best choice because of it wide coverage of the 3 kit len
ses. If you have the intention to invest in your len
ses collection in future, than 17-85mm is a good len
s to start with, it have a very good feel and balance with the 50D body. Personally, I would not go with 18-55mm len
s as the range is too narrow and is too light for my liking on the 50D body. Beside, you may not always have the opportunity to swap len
s when you are on the go, so having a longer range is always better.
I have both 17-85mm and 18-200mm and a 50D body, I would bring my 18-200mm with me on casual holiday and 17-85mm along with my 70-300mm for more scenic holiday or photography outing with friends. Everyone have their different photography habit, guess it is up to your personal preference.