I've got both the 17-55IS and the 24-105L both are fantastic. But I think I am going to be sticking with my 24-105 now that I have both. Sure its not as wide but lately when I need wide I've needed really wide so the 10-22 comes out anyway. Which then makes the 105 much more appealing in the walk around sense.
Of course I can't bring myself to get ride of either and I still have a hard time deciding which one to put on the camera when I got out.
another vote for the Tamron 17-50/2.8 U really dont need a IS for this range. I have shot sharp handheld shot at even 0.3secs. This is an excellent lens.
Cons of this lens are- below average plastic material, and result in loose front element over a period of time (will be rectified by Tamron for free though as this is somewhat common for this lens)
well I can't speak for Mountain Biking and Snowboarding usage but the EF-S 18-200 is a great travel general purpose/family snapshot lens. I spent a week in San Francisco with it as my primary walk around lens. It did a fantastic job and my back really appreciated not carrying three or four pieces of glass up and down the hills.
the lens is much maligned but usually by people who have never used one or who will have nothing less than "f2.8 L" in their signature.
