The Wii is a family system and the PC is kind of a single owner thing.
Wii is great for party's and such, but then again PC's are great for LAN Party's if you have them.
Hontestly, out of the two, I would go for the computer. Just because they allow you to do so much more. The Wii is restrictive as to what you can do with it. Its sole is for interactive games. With a compter you can game, listen to music, browse the internet, and then you have all the applictations, homework use. Everything. The computers entertainment brings very few limits.