@mwichary the main 24pin power connector for ATX motherboards, it is absolutely disgusting to insert and remove.
It feels like you are going to break the motherboard while inserting, as it takes unreasonable force. And it takes minutes of wiggling while holding the lock tab open to remove, it almost feels like you're ripping the pins out of the solder joints.
It also comes in two parts you need to hold together while inserting, and often does not make any noticeable confirmation, you need to inspect visually if it's properly inserted.
Thankfully it's an one-and-done type deal, rare to have to ness with it, but when I do it's usually because there's new-to-me hardware involved and it is terrifying.
The worst part is, it isn't even retro! It continues to disgrace this earth to this day.