What you're doing when you contribute to Child's Play is buying toys, games, and books for children mostly in long-term care. It's an admirable gesture as people in hospitals must be bored as hell and in need of some good entertainment. But still, I don't like the idea of gamers giving games to future gamers.
It reeks of consumerism. It's no wonder why Microsoft, Sony, Blizzard, Valve, etc. all give thousands of dollars to the cause every year - it's great PR. It creates new customers. Furthermore, if I remember correctly, the reason Child's Play was started was to give off a good image of gamers, and to shove that in the face of politicians who would claim that they're violent, unbalanced individuals. Well that's great guys! You sure can buy video games. You sure showed them.
Here's the most important part: Child's Play doesn't save lives. I guess you could give a lot of excuses and pass them off as arguments: "the more money we contribute to entertainment, the more hospitals can pay for medicine!" or "kids won't die... of boredom!" But that's bullshit. Kids don't die of boredom. Kids die of hunger, disease, violence, and a whole lot more. Video games won't save them.
Look, it's great that you're bolstering an entertainment industry while giving toys to children in first-world hospitals (oh, and one in Iraq), instead of buying the same things for yourself. But please consider donating to charities that will actually work toward curing actual ills. They're very easy to find.
I'm open for arguments as to why I'm off base about Child's Play, but it probably won't deter me from my main argument that there are much better ways of giving away your money.
PS In Child's Play's favor: according to the Wikipedia entry (but not the official site?), cash donated does go toward "paying for pediatric research, facility improvements, etc." If true, that's great.