I have the EF-S 60mm f/2.8 USM Macro lens and it's the sharpest lens I own. Focusing is a little slow but it's a fun lens to shoot with...DOF is crazy when you're wide open at MFD.
Canon XTi
EF-S 60mm f/2.8 USM Macro
Shutter Speed: 1/60
Aperture: f/2.8
ISO: 200
Focal Length: 60mm
Light Source: Small LED flashlight camera left