The worst ever was my ex-stepfather's funeral. My mom divorced him suddenly and married the man she was having an affair with very adruptly when I was in elementary school, and while she let him have visitation growing up after that, our relationship became more and more strained. My mom had a made a point of reminding him over and over that I wasn't his child, and made a lot of nasty comments and accusations against him to drive a wedge between us. There's a long back story there that I won't go into, but by the time he died (quite young) I was in many twenties and had only gotten to see him a couple times in the handful of years previous. I wasn't allowed to come see him when he got very sick, only my brother, his only "real" child. I was beside myself, but didn't say a word, not wanting to upset anyone.
There was no real funeral, just a massive party out at his house, a bonfire, and a huge potluck and a lot of booze.
His wife when he died (he was married a few times) cremated him and never bought a proper urn. She bought one of those cheap wicker boxes from Walmart and stuffed the bag of ashes into it. No one talked to me and my sisters; everyone stared at us and whispered openly to the people around them, but not one person approached us and said a single kind word. Hundreds of people there.
There was a huge fight about the ashes, and it took years before his ashes were finally buried and a stone put up. The spot that was chosen was on the middle of nowhere, and took forever to get to. The family busted out a cooler of drinks once we laid him to rest, and by the time we got back to town, I was loaded on whiskey, and feeling good that I had been included in something that was so important to me.
We went back to an uncles house, and the widow came over and asked my brother to come to her house with her. After a pause, she said, "You, too" to me and we all drove to her house in separate cars.
I thought we had been invited over for lunch maybe, that she might talk about dad, but she spent an hour running around her house, piling some of my dad's belongings in front of brother, and then directing me to carry it all out to his truck.
She was left everything, and had never passed down any of his belongings until then. My brother was born right before my parents divorced, and barely knew him. The worst part was watching dad's entire record collection being handed to my brother. I have a lot of memories of playing those records with dad and it was like being punched in the gut to see them again, let alone watching them being given to a sibling that had no association to them.
Dad was a successful business owner and left all of his assets to his wife. All I cared about was being acknowledged as his kid and maybe being gifted with at least some of those records. It would have meant the world to me.