If your radius is a couple hours drive, the world is pretty much your oyster. Locally, Valley is the biggest name but highly pressured with very educated trout. You've also got the Brandywine, French Creek, and the Tulpehocken...all within 20 to 50 minutes. If you are willing to venture further, you can get into the PA limestone in the Poconos and Lehigh Valley such as Monocacy and the Bushkill. If you have up to 3 hours to drive, you can make it out to Central PA for some of the classics out by State College like Penns, Lemont, and Little J. A great option is to do a half day guided (DM me if you are interested as have two good names).