Canon 550d lens recommendation for replacing the 18-55mm kit lens

but again, we face here another softness problem called diffraction, most lenses start to become softer when we use them on crop sensors by getting to f8 or f11, that is one reason we pay so much for 2.8 zooms like 70-200 or (24-28)-70

but there is other factors much more important than the lens quality, for me it is a steady shot especially for landscape, never ever shoot without a tripod, even in a bright sunlight.

this way we can shoot in a lower ISO, smaller aperture for more DOF and a shake free shot.