There's no risk between buying a PS3 and the Xbox 360 S. It's all a matter of taste and/or your budget. Granted, buy an older model 360 and you're flirting with disaster.
But there are trade-offs between the consoles. In general, visual fidelity of multiplatform games is better on the 360. See: Crysis 2, Bayonetta, and most Call of Duty games. You have some great online service, and there's much fun to be had with the Xbox LIVE Party feature. And the controller feels very comfortable in your hands and Kinect is pretty damn cool. You do however, have to pay monthly/annually to use Xbox LIVE in its entirety. They have a restricted version for free which sadly doesn't let you play online.
PS3 is more of the Swiss Army knife. You have your games, but generally you sacrifice graphics for free access to online multiplayer. At least, that's how I see it. For me, the PS3 is more cost-effective. I can access the Internet, browse my Facebook, watch my HD movies, etc, at the low, low price of $0.00 a month. And if you ELECT to use the PS3's paid service, there's a mighty fuck ton of rewards. Early access to demos, deals all across the Marketplace, etc. I like the 360's rewards program a little bit better in that when you pay for your monthly fee, or you buy select content, they actually reimburse you some of the cost, in Microsoft Points. I haven't seen Sony do that yet.
In the end, it's up to your own personal taste. I personally miss the enhanced graphics when it comes to multiplatform releases, I miss the Party chat system (You're only allowed 1 on 1 conversations on PS3), and I miss the fuck out of Bad Company 2. But I think playing the same games, albeit with reduced quality, for free is much better. I'm personally financially tight, so not having to pay monthly was the selling point.
If you or your family has disposable income, get a 360. If you're on a month-to-month budget, get a PS3.
