For your 60D, I think the 15-85 is still your best option for a walk around lens, and it sells for around $750. Canon doesn't have any EF-S "L" lenses for some reason, but the 15-85 and 17-55 are fully "L" quality. Personally, I think the 15-85mm is superior to the 24-105L optically and has a much better focal length (on the wide end) on a crop body.+1000
Any of the standard zooms with an L designation start at 24mm, which is 38mm equivalent on a 60D. That is just not wide enough for a general purpose zoom.
The EF-S 15-85 and 17-55 both hold their value pretty well also if you plan to sell later if you move to a FF body.
Entirely agree. If you are buying just one lens for the 60D, get the 15-85. When you multiply by 1.6 to get the FF equivalent you have 24-136...