M.G.
Five of my kids have this same problem, and it runs in my family, as well. Bedtime is insane because they sit in there and talk to each other all night. We start the "calm down" routine right after dinner, and it seems to work until they are in their beds. Then, all it takes is one kid being willing to start something and they are all up and at it again.
I wish I had some great advice here, because I could use it myself, but I just want to say I totally understand. One of them is an avid reader, so a book will keep him in bed, but I will walk back there at one or two in the morning and he is still awake reading. I have to remember to take the book away after the other kids fall asleep or he will be up all night.
I did start waking them up early and that seems to help. I hate doing it, though, so I'm not very consistent with it -- I just can't seem to bring myself to wake up sleeping kids! lol
Good luck.