Well seeing as they are all CAS 5 then the biggest difference is the OCZ name on them, which is an excellent name in desktop memory. However make sure your laptop supports added memory, since not all of them do.
So all in all I would go with the OCZ ram because in my opinion it overclocks well, but if your not going to do anything like that then go with the PNY RAM because of the price.
EDIT : I looked again and I noticed the OCZ RAM has a mail-in rebate, so if I was buying it I would definitely go with the OCZ RAM.