It depends on what your situation is. The Philly area pretty much has it all. If you have a family or are planning to start one soon I would say the western suburbs in PA and DE or Southern New Castle Co DE are good. Look at Bear and Middletown DE. If you're single or looking for more night life I would look around the university towns on the western and north western sides, Claymont, DE is another place a lot of people live. I'd recommend staying on the west side of Philly, less hassle with traffic.