A Sony PVM-1442QM CRT... The tube was intact but the connectors were smashed inwards and as soon I turned it on, my house's breaker popped as something inside the monitor broke off and was shorting against the 240V input.
I didn't bother and sent it back, asking for a refund in the way (paying 450 euros for a monitor and for it to arrive damaged'.. No thanks!) thankfully the seller was understanding and was sympathic enough to ship me another one, free of charge 😀 since this PVM has been sitting at a friend's place, hooked to an Apple IIGS
Then came a Mac IIfx, it arrived in pieces, metal chassis was bent by the hard drive banging everywhere... 😵 this time the seller (a young guy who clearly knew a lot about 68k macs) didn't make a fuss too (he told me that "shit happens" sometimes) and refunded me without further ado.
An XT/286 I got years ago, seller only sent the motherboard naked (no case nothing), I guess you can see where this is going: motherboard arrived cracked in half 😵 and to rub salt into the wound, seller blamed me and told that I broke it on purpose... Needless to say that police quickly got involved (seller started harassing me and sending death threats) for this one.
Edit: to clarify the last one, the guy who sold me the broken XT/286 mobo was already known for blaming the buyer should something go wrong with a transaction, it wasn't the first time he done that. He had a report or so on some website (that today no longer exists, as this ordeal happened roughly 7 years ago).
Proud owner of a Shuttle HOT-555A 430VX motherboard and two wonderful retro laptops, namely a Compaq Armada 1700 [nonfunctional] and a HP Omnibook XE3-GC [fully working :p]