The non-Grinch part of my message is: there are better places to find pleasant surprise than gift-giving rituals. Indeed, detaching gift-giving from ritual occasions seems to increase the surprise.
I'm sure it would increase the surprise, but it also decreases the anticipation, which is part of it.
Personally, the gifts that I got the most enjoyment out of were usually video games; I'll revisit a good video game many times, even after the system has become outdated. Whereas I've bought most of my favorite books myself, most of my favorite games were given to me. However, given the choice, I would not have asked to receive only video games for Christmas, first because receiving several games rather than one or two would probably have resulted in a decrease in their average quality, and second, because it would prevent anyone who had a really good gift idea that wasn't a video game from giving it to me.
On average, I would have probably received a greater total enjoyment from my gifts, but I would have lost much of the mystery and anticipation. The experience of knowing you might get something special and unexpected has utility in itself.
I've long entertained a dubious regard for the practice of lying to children about the existence of Santa Claus. Parents might claim that it serves to make children's lives more magical and exciting, but as a general rule, children are adequately equipped to create fantasies of their own without their parents' intervention. The two reasons I suspect rest at the bottom line are adherence to tradition, and finding it cute to see one's children believing ridiculous things.
Personally, I considered this to be a rather indecent way to treat one's own children, and have sometimes wondered whether a large proportion of conspiracy theorists owe their origins to the realization that practically all the adults in the country really are conspiring to deceive children for no tangible benefit. However, since I began frequenting this site, I've been exposed to the alternate viewpoint that this realization may be good for developing rationalists, because it provides children with the experience of discovering that they hold beliefs which are wrong and absurd, and that they must reject them.
So, how did the Santa deception affect you personally? How do you think your life might have been different without it? If your parents didn't do it to you, what are your impressions on the experience of not being lied to when most other children are?
Also, I promise to upvote anyone who links to an easy to register for community of conspiracy theorists where they would not be averse to being asked the same question.