I think the worst are Business Post.
I once ordered two crates of Bud Ice online since they stopped selling it in shops. It didnt turn up, so the retailer sent me two more. I got carded and went to collect and they only brought out one. Apparently someone dropped one and it smashed all over the warehouse floor. Retail sent me another, which got delivered fine. About 2 weeks later a guy turns up with 2 more crates. It was the original ones that had been put away in a locked cage because it was alcohol and had been forgotten about. Result, but still total idiots.
Then last year I ordered some special sand for my aquarium which comes wet packed. Got carded, went to collect and was presented with two soaking wet boxes with sand pouring out of them, bags half empty. Seems half the sand was all over thier warehouse floor along with my bud ice! So I refused to take them. Shop sent replacements - Again sodden boxes, although this time the sand was present so did take them.
Total noobies.
I think it depends where you are in the country. DPD for example, here are always ok (apart from he hammers down the door full on for about 20 seconds!) but I know others who say they are always late / damage stuffs etc, but they are all self employed franchisees with DPD, so you dont know what you are going to get. A lot are going that way now.... DHL.... Hermes..... obviously cheaper for them not to maintain thier own fleet that way.