This is from one of our favorite parenting books (Love and Logic). The basis is that children need to be raised to learn how to make choices for themselves to help set them up for when they don't have parents telling them what to do in every situation.
So before bed would look like this...
Us: "Do you want to go to bed now or in 2 minutes?"
Child: "2 minutes" (always)
Us: "ok, we'll go to bed in 2 minutes"
After a span that was probably never 2 minutes...
Us: "Ok it's time to go to bed"
Child after being trained in this: (goes to bed)
Child before being trained in this: "No"
Us: "Do you want to walk to your bed or have us carry you?"
Child after responding with more "no's"
Us: (carry them to bed)
You get the idea. Obviously while the child is learning this the scenario can go on as they may get out of bed, but I'm not typing out the whole book :) It's a great read for any parent!