My children ask me each year the same question. After thinking about it, I'm deciding to give them my real answer:
What do I want for Christmas or my Birthdays? I want you. I want you to keep coming around, I want you to bring your kids around, I want you to ask me questions, ask my advice, tell me your problems, ask for my opinion, ask for my help. I want you to come over and rant about your problems, rant about life, whatever. Tell me about your job, your worries, your significant other, your kids, and your pets that I hope you have. I want you to continue sharing your life with me. Come over and laugh with me, or laugh at me, I don't care. Hearing you laugh is music to me.
I spent the better part of my life raising you the best way I knew how, and I'm not bragging, but I did a pretty good job, no matter how chaotic it looked (or felt) sometimes. Now, give me time to sit back and admire my work, I'm pretty proud of it.
Raid my refrigerator, help yourself, I really don't mind. In fact, I wouldn't want it any other way.
I want you to spend your money making a better life for you and your family. I have the things I need. I want to see you happy and healthy.
When you ask me what I want for Christmas, the real truth is that I want you to spend time with me.
FYI -I didn't draft this up but copied and pasted because I thought it was AWESOME. It's exactly how I feel.