747 is a pretty good credit score - so obviously carrying 3 credit cards has helped you establish a decent credit history. Even though it could be higher, you have a good chance of getting approved for most standard
credit card offers. The fact that you've already been approved for 2 non-student credit cards is a good sign that most issuers would approve you for an additional card. At this point, it's probably not necessary to cancel any of your existing credit cards since you only have three. Unless you're uncomfortable with having 4 credit cards, I would leave the other ones open and find a new 0% APR offer. If you still want to cancel one, choose the highest interest rate offer (probably the Chase Freedom).