Getting kids to go to sleep?

I am really going through a HARD time getting all my kids to go to bed and stay in bed at night.

I have children who are 11 (girl), 6 (girl), 4 (boy), and 2 (girl). They all have their own rooms, the 4 and 6 year olds used to share and had a playroom, but were seperated just over a year ago. The older three have upstairs rooms, and my 2 year old has a small bedroom downstairs.

My 11 year old used to have no issues going to bed, never did have really. Now with the middle two messing around, she is getting herself in trouble by staying up and playing with them instead of telling them to leave her room or coming and telling me they are up.

The 6 year old went through screaming fits from 1 1/2 until she was about 3, we have had ups and downs with her going to bed when she is told. Right at this moment (the last week) she is not doing all that bad, but she has a cold and has been run down.

My darling son (4) was a nightmare about staying in bed, and would keep the others awake. He did alright for a while, I got him some computer games (hooked on phonics he LOVES) and a gameboy advance, and he would get grounded from them each day if he did not go to bed the night before when he was told. One warning, then lose privelages for the whole day. Recently my husband has stretched it out where the worse bedtime is, the longer he is grounded, and I really think at 4 it should go day to day... sometimes it is a three day stretch and I think he loses the focus of the whole thing that way. The change came from adding the two older girls in on the same system to try to get them all to do better. I personally am thinking of going back to the other day where each good night earns one day of games for all three of them.

Amazingly, my 2 year old daughter goes to sleep sooo easy, even though she is in a bed already. We do use a baby gate in her doorway, but that is more at naptime when she wants to get up and play because it is light in her room.

So after dinner everyone is in and out of showers (no tub in this house), then gets out school clothes as needed, brushes teeth.. the usual. Sometimes we read, sometimes some quiet TV time and cuddle up together on the couch, we also sometimes try playing games, but the middle two still get frustrated easy so we usually do that during the middle of the day...

Send the bigger three to bed while I get the little one ready. I put her to bed and go tell the others good night. Many times when I tuck them in I remind them that they have to go to sleep without getting up to earn games the next day.

Most nights lately, I hear the pitter patter of little and big feet as soon as I walk below their rooms, about the time I get to the bottom of the stairs!

Back upstairs, one warning is all they get about games, and tell them they need to listen to me.

Pitter patter... ugh.. back to the bottom of the stairs this time as I am getting tired of the climb. tell them they lost games and need to go to sleep NOW!!!.... Giggle giggle/pitter patter/stomp/giggle...

Anyone have advice for me? I have tried closing their doors, but we have wood heat and it does not circulate well with anything closed, and it did not work to keep them quiet.

I have sat up in one room or another to get them to go to sleep and then sit with another to keep them still long enough to fall asleep... I end up staying up later then normal doing this and tired in the morning.

Don't get me wrong, they do always go to sleep well before I usually do, but it just works me up so much to have to keep repeating over and over and over. I would love to find some way to get them in the habit of listening at bedtime.