What lens is on your camera most of the time ?

Currently the 15-85 stays on the 60D 98%, with the 18-200 or 50 1.8 on the T2i.

I was in a delima between the 15-85 and the 24-105 -- but for myself the 24mm just was not wide enough to get the 24-105 as a good quality general purpose zoom.

I have the 55-250 IS, but with the 18-200 and the 55-200 lenses I have at 200mm the 18-200 is sharper than the 55-200. Maybe my 55-250 not a good sample but so far my results are very similar to the-digital-picture.com's "Digital SLR and Lens Image Quality Comparison - ISO 12233 Chart 100% Crops" between the 18-200 and the 55-250:

http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=476&Camera=474&Sample=0&FLI=0&API=0&LensComp=456&CameraComp=0&FLIComp=0&APIComp=0