Oh lord anything but priority mail. I used to work for the Post Office in the Distribution center no less and let me tell you priority mail gets treated like it's a plague. There are what they call cans about 10'-12' away from the postal employee behind the conveyor belt. I've seen these guys play football with priority packages and slam them in the back of those cans. If they suspect their was food in some of those packages they would really slam them into the back thus busting some of them and then since they were perishables get to take them back out and then pass them around (cookies and such) and eat them. And don't ever put fragile on the package that's just asking for a broken item when delivered.
First class mail areas is much better since they use sacks in a square around the employee and these are just hand tossed about 2'-3' away into those sacks and I worked that area during my career.
So, if you see a dented game box or package you'll know what happened to it. Someone threw a touchdown with it. lol I've gotten some dvd and cdrom cases that were fractured/cracked because of being sent priority mail.