For me, that's been FedEx.
I had some medication overnighted to me for delivery on a Friday in July. I was home all day, with the front door open, and around noon the tracking changed to no answer, but there was no slip. I called them, they got confused and sent someone out to pick up a package from me. When I asked about my package and told him I didn't in fact have a package for him, he called the other driver - small town, apparently only 3 FedEx drivers - the guy swore up and down that he tried, but he'll come back because I needed that package that day.
When he showed up, he apologized, he left the slip on the wrong house - never even came close to mine. It worked out in the end, but it was a huge hassle.