Winner but doesn't count: Estafeta
My very personal experience while being in SE Michigan goes this way:
1) Airborne Express at OfficeMax (now DHL) with the best rates, the fastest gorund service, real time tracking, careful with the packages and the convenience of location at each OM. Did I mention that very often OM has coupon to make the shipping even cheaper?
2) FedEx. Ground service similar to above, but a little more expensive and takes a day longer. Express saver may be the best combination of price and speed.
3) USPS and UPS. USPS is fast, UPS is more reliable. Still airborne ran circles around them.