Overall, I would have to vote for UPS. Yes, they have a problem from time-to-time, but 99% of the time it gets there and most of the time, whole. In my experience, anyway.
I like Fed-EX Air, too, but they won't leave anything at the door with no one home to sign, even with a big signed letter pasted on the front door.
USPS is just great when it works, but when it doesn't, you don't know where the item is or if you'll ever see it. I think you have to wait 4 or 6 weeks to file a claim, too.
Sent a Long antenna to Alaska via FED-EX a few years back. Fellow called me and asked why I sent him two antennas when he had only ordered one. I asked for the two model numbers and, as he looked for them he found that the carrier had cut the antenna in half and re-taped them. Probably to fit into a smaller plane.....
Never saw them back, just a check for the insurance.