I need help picking a lens! [time sensitive]

[weepete]

Canon 15-85mm f3.5-5.6 IS would be my choice. It's pretty sharp and though not quite L glass quality no one makes L glass for crop sensors. The 28-105mm lenses are great for that flexible reach but (and bear in mind I shot for a number of years with a 28-105 on a crop sensor camera) it's a weird focal length range on a crop sensor that at the end of the day just isn't wide enough and can get you stuck in that middle of the road telephoto range.