If you stopped using your PSN account after the hack, you can ask for the contents of your wallet to be reimbursed. If you kept your PSN account and participated in the "Welcome Back" promotion, you can choose an additional game from a list consisting mostly of the "Welcome Back" games, or you can choose three dynamic PSN themes, or half off three months of PlayStation Plus. Qriocity accounts are entitled to one additional free month. SOE accounts can request repayment of wallet balances for no-longer-used accounts, or $4.50 in "Station Cash."
There is a separate claim form for PSN users who suffered losses from identity theft as part of the hack.