I completely understand what you are going through. I have used co-sleeping with my son since birth and have treasured it. I wouldn't trade this experience for the world. It does make transitioning into their own beds really difficult.
Now that I have transitioned my 3 1/2 year old into his own bed, I have some advice that worked for me. This is a 3-part plan.
1. For every full night of sleep in his own bed, I would allow him an instant gratification toy (cheapy toy $1-$5, hot wheels, sand bucket, shovel, toy bugs, etc.). He knows where the "rewards" closet is and he was able to pick out his reward for each FULL night of sleep in his own bed. Half night of sleeping in own bed = no toy.
2. For every full night of sleep in his own bed, he would put a reward sticker on the calendar. For every X stickers (I used 5), he got a bigger toy (monster truck, dvd, piece to the Thomas collection) also out of the "rewards" closet that he was able to pick out. He knew he had to count the 5 stickers to get to this event. So he had X nights to go before he could get another toy. Half night of sleeping in own bed = no sticker.
3. Then after 2 months of this type of rewards system, I implemented a bigger one... if you can spend 30 consecutive FULL nights in your bedroom, you will get the big finale reward and we are completed with the project. I let him pick it out. He wanted a scooter. 30 consecutive stickers later... he got a toddler scooter.
Total cost to implement this, probably around $150 (over a period of 3 months) but could probably be done a lot cheaper if you used less expensive toys. It worked well and the instant gratification combined with teaching him patience to wait worked well. Plus for me, the counting, adding and subtracting element was an additional bonus to teach him.
I used the same technique for potty training, modified slightly... instant rewards and then the sticker chart with X stickers rewarding a bigger toy.
I think everyone else has covered the topic of the TV in the room... :)
Good luck.
L.