I’m the father of two kids AND I work for Sony designing videogames. As you can imagine, we’re a very pro-videogame household.
First, if you can wait until Christmas there’s probably a big price drop coming. XBox is releasing it’s next generation system then and Playstation and Nintendo will probably slash prices on their existing systems in response.
The Sony Playstation has the largest market share and the largest variety of games.
Microsoft’s XBox has fewer titles, but a few of them are really, really popular (Halo, for example). The XBox also has the most powerful hardware of the 3 systems (although the difference is pretty marginal).
The Nintendo Gamecube has the smallest selection of games. Nintendo tends to focus more on “kid” games. They also tend to focus on quality over quantity, so even though they have the smallest selection of titles, many of their games are excellent.
I’d ask your son what system his friends have and what games he’s interested in playing. If all his friends are playing a particular game that’s exclusive to Playstation, and you get him a Gamecube he may be disappointed. (In our household we have both a Gamecube and a Playstation 2 and my 8-year-old son tends to favor the Gamecube slightly.)
You also might want to consider a handheld. My son actually plays his Gameboy more than he plays games on the TV. Handheld games are cheaper and tend to be more strategy-oriented than the more twitchy console titles. (For a while we joked that he was teaching himself to read by playing Pokemon.)
There are two new handhelds that just came on the market: the Sony PSP and the Nintendo DS. However, for a new gamer I would recommend getting the previous generation Nintendo handheld: the Gameboy Advance SP. They’re still being sold and they’re relatively cheap and there’s a large library of games to choose from.
One other thing your should be aware of: the game rating system. The game industry has a very good rating system that can help you as a parent determine if a particular game is appropriate for your child.
The ratings are:
A/O – Adult Only. (NC-17, very few games get this rating)
M – Mature. ®
T – Teen. (PG-13)
E10+ – Older kids. (PG)
E – Everyone (G)
EC – Early Childhood (as mild as “E”, but geared toward very little kids)
You can read more at the Entertainment Software Ratings Board website.
(For example, my son knows that “M”-rated games (of which I own a few) are totally off-limits and that he’s allowed to play “T”-rated games only if I am familiar with the game and give my okay.)