Here are my favorite Dear Santa letters I've found:
Tiny, Timid, yet Tenacious
Hi. How are you doing?
Don't gimme that Jibba-Jabba, I wasn't talking to you. I was talking to myself. You don't deserve for me to write to you, I only wrote you this letter to waste your valuable time. While you stuff your face with everyone else's cookies you'll think back to this letter. Then maybe you'll have the New Years Resolution to lose weight. You fatty. I pity the foo.
(That's the Grinch to you!)