I prefer a bit more working distance than a 55 or 60mm lens will allow. I have a Nikon 28-105mm D lens, which is not strictly a macro, but it does have a good close focus capability, and it is sharp. My "real" macro lens is the Tokina 100mm f2/8 macro, which is sharp,and a very good lens. Tamron also makes good lenses, and Vivitar used to have a 100mm f/3.5 macro lens that was said to be excellent.
I have found that the macro feature on the 28-105 gives me about 80% of all my macro needs.