Remotes
Bastards breed, they also have suicidal tendencies, they seem to coat themselves in an invisible slippery field guaranteed to end up with the damn thing bouncing on the hardwood floor springing it's battery cover (if it still has one) and occasionally batteries too. In my living room there are 8 remote controls, AC and Fan (both items are essential at this time of year although their need for a remote is dubious), TV, Satellite system, Amazon Fire Stick, HTPC (X10 rf), rf keyboard and mouse for gaming PC, and rf mini keyboard and touchpad for HTPC. The TV and Satellite ones are supposedly multi remotes but they only cover the essential parts of the device it wasn't designed for, so if you want to mess with the screen or audio settings then you gotta go hunt for the original remote. STB should come with QWERTY remotes, searching for something using a phonepad is a pain.
Neat trick for those of you who don't know if you have an IR remote that you think is nadgered switch on your camera phone and point the remote at it, the sensor in the phone is IR sensitive and so you can see if the transmitter is working when you press a button.