Owning both, I'd say that it all depends on a few basic questions.
1. Do you really, really want to play FFXIII Versus?
If yes, PS3 is the only console you'll get it on. This is one of the main reasons I got a PS3, although there are others.
2. Do you want to play local multiplayer (ie, with two people sitting next to each other both playing on the one screen)?
Xbox 360 is much, much better for this. With PS3, only one account can be logged in at a time. This means that if you want to earn trophies together, you have to do it logged in as one person, and then all over again logged in as the other person.
3. Do you, in general, prefer single player games or online gaming?
If you prefer single player gaming, I would say the PS3 is better. If you prefer online gaming, it's about 50/50. I think the Xbox 360 has better online games, but at the same time I think the cost of Xbox Live is pretty nasty, especially if (like Danielle and I) you have two accounts to pay for.
4. What do most of your friends have?
Because if you want to play with your friends, you're going to want to have the same console. Cross-platform multiplay is not a common thing yet, sadly enough.
5. Which games do you prefer?
This is for some people the be-all and end-all when it comes to picking out the console - especially for people who don't like multiplayer games. If the console has more games you prefer - and more future releases planned that pick up your attention - then obviously you should favour it.
