Which SSL do I need?

Standard SSL : It verifies the Domain Name and the identity of the web services on this Domain Name and it guarantees at he communication is encrypted.
Premium SSL : It verifies a Domain Name and the identity of the associated institution , and it also guarantees that the communication with  web services on this domain to be encrypted.
EV SSL           : Offer the highest available levels of authentication across any SSL certificate type.The green address bar prominently displays your company name and provides highly visual assurance to customers that your site is secure – immediately giving them the confidence to complete their transaction.