The big three all suck.
I have had a bad expeirence with USPS, UPS and FedEx.
That being said, UPS sucks the least.
You can't beat the USPS Priority Mail for $7.95. It is a flat rate up to 70lbs! I shipped a pretty heavy damper once and giggled all the way home.
The only down side is that the 3-5 business days is not guaranteed. I got burned on that once.
If it has to be there positively, absolutely overnight...it's UPS. (IMHO)
Haven't tried DHL yet.
-John