A big reason, is that many presents end up occupying space, and space is expensive, and leads to the miserable, "where do I put this", which is closely followed by either, "what do I need to throw away so I have space to put this", or the "uh let me leave it over here while I figure out what to do with it".
I didn't have much experience with the present exchanging thing in childhood, but I can see how its fun, but then, in the morning, there's still the question of what to do with it.
This means that I tend to prefer things that are practical so that they can replace something less useful in my life, or are something consumable so the problem of storage is only temporary.
Though there's also the possibility of digital goods like some albums from magnatune, or some RPG supplements/comic book from http://rpg.drivethrustuff.com/
because I'm too lazy to make a specific wish list, and somethings aren't purchasable, here's some things I'm interested in.
Take stuff! I have stuff I don't need any more, making it go away in an environmentally safe way makes me happier.
this shirt would be neat
Albums by Nightwish, Within Temptation, Brad Sucks, Epica/The Phantom Agony, Marina V's new album
some help doing this
High grade chocolate or cheese is also appreciated.
Another power brick for a X61 Tablet.
Dunno what else.