Kids' Bedtime Battles

I always have this recurring issue where bedtime for my kids feels like World War III. They drag their feet until it's almost too late, and the entire process turns into a marathon of negotiating, distractions, threats (which I never follow through with), and eventually, tears from both them and me. By the time they finally fall asleep, I'm usually so exhausted that I just collapse on the couch for a bit before bed myself. Anyone else deal with this? What are your tips to make bedtime less of a battle?