Get out of town!
College might be your ONLY chance to live/work/play in a different part of the country, or a different climate or time zone. Did you grow up in a suburb? Want to try the big city without making a big committment? Getting out of state can really fill the bill for many of these scenarios. Going to school out of state will also expose you to students from different parts of the country and the world. Diversity can be a great learning tool, and you might learn a lot more about yourself than you would if you stick close to home with the same type of kids you've always known. College is about taking risks in a safe environment....so if you want to risk a cold winter, or the mountains, or NYC, then going to school out of state might be the answer.
On the flip side, maybe you're not ready to go too far from home. You might have family obligations, or you just need a couple more years to really mature before you go too far away. If that's the case, then staying in state is probably a better choice, but you can still try to get out of your comfort zone by choosing a school with a different ethnic or socio-economic makeup than your high school.
It's all about the right fit, but don't forget that even those really comfy Ugg boots wear thin after a while, and sometimes its a good idea to try a new style or color and find out that what you THOUGHT was your "right fit" might not be exactly what you needed after all.