I have a tv that has an led to display that it is off. LED is obnoxiously over used for displaying things no one gives a shit about. But personally my pet peeve is the annoying beeping everything does. It doesn't provide any context or useful information. I've been at a self checkout and have the clerk turn it back on after I muted it while scanning items. It resets after the transaction anyways. Everything has beeps or bright LEDs.
Phones are my biggest complaint - not mine as all sounds have been turned off, but everyone else’s. You get a sound when you receive a message, when you unlock it, when you type a message and when you send a message. It’s just so pointless and annoying.