It really depends on what you want to do with your life. If you like school, you should stay there. Corporate life is really different, and it will be a bit of a shock at first. Most PhD careers are teaching and research. There are exceptions to this, but that is a major path for most people choosing that route.
There are advantages to leaving school, pay will be higher (at least compared to graduate school), and you won't be studying all the time. On the flip side, you'll have deadlines that can be arbitrary and business politics.
Having been out in the real world for a while, if I had to do it again, I would probably pick graduate school. Having a good job is great in all, but eventually you'll realize that a lot of what you do at different places will be variations on a theme. At times the work will be fun and really challenging, but if you aren't working at a place like Google, Microsoft, Apple, or a place like Fog Creek, the work will get repetitive.
Here's the other thing to think about. At least in the US we are in the middle of a major recession, which could potentially get worse. Getting into grad school can somewhat insulate you from this. They have grants, loans, TA and research work. It's not a ton of money, but normally it is enough to live off of, and you get to stay in college.