I also have a high spirited toddler. When she was 12 months, I decided to do the cry it out method to get her to sleep. Everyone says it takes about 3 nights. It took us about 3 months. Unfortunately, I think the only thing that will work is for you to let him cry it out. I cried almost every night with her, but I had no other options as I was expecting our 2nd child and could not have to children up all night long.
My sister in law gave me some great advice. She had watched an episode of that nanny show where the professional nanny comes and helps homes with out of control kids. The problem was a child that would not sleep or stay asleep. Anyways, consistency was the key. You have to put him in bed and leave him there. You must NOT give him anything to look forward to or any incentive to stay awake. So, don't give him anything he wants or pay him any attention. You can't even speak to him or look him in the eye. It's hard because you think that your child will not think you love him. Believe me, by 15 months and how much you care about him, he KNOWS you love him. He is just taking advantage, which is what my little girl did until she knew I was serious. So, it will be extremely difficult for you, but you must leave him in his crib and let him cry until he falls asleep. He will get the point that that is how it needs to be, and eventually he will go to sleep without a fit. My sister in law said that you can stay in the room for a while. At first, you can stay near the crib, then each night, move a little further away. Just make sure you don't communicate with or look at him.
It's so difficult, but he will not be emotionally ruined. It will probably be the opposite. He will know that mommy is boss and not him. I feel that it has been very good for my whole family that we made it through that rough spell. Also, you will feel bad when he does finally go to sleep. I would sometimes cry myself to sleep because I felt like a monster and would wonder if my daughter would be depressed in the morning, but she was always so happy the morning after.
One more thing, routine is very important. Try to put him down for naps and night time around the same times every day. He needs you to set the rules and conditions.
I almost forgot. Before getting my daughter to sleep, I rock her and sing a special song to her. I do it every time. It kind of helps her chill out a little. Then, I give her her favorite teddy bear or baby doll or both. I read that it helps them find comfort other than mommy's arms or bed. Anything will work like a bear, blanket, or any other kind of "woobie".
Good luck!
P.S. It may take hours. Some nights took up to 3 or 4 hours. You'll be sleepy, but once it works, you will get all the sleep you need.