<p>Agree that if the costs are not a big deal, go to Michigan. You will find friends there – I did! 
And I am kind of an introvert. Some people from my high school went to Michigan when I went, but honestly I did not hang around with them a ton. One lived down the hall from me, so I saw him quite a bit. But the rest were spread all over a large campus, so pretty quickly it was easier to do things with people from my dorm and the activities I joined. Since Penn State is also really large, it would probably be similar for you. So I say don’t pick based on where your friends are going. Try something new where the academics are more challenging.</p>