Killzone4 would be for me Mugan!
Also I'm thinking they will announce and show the PS4 along with 3/4 games so say Killzone 4, Wipeout plus 2 new IPs. Then maybe 2 3rd party games Star Wars 1313 or something. Then expand that at the event a few days later when they announce something else.
E3 MS are planning there xbox showing to which I expect Sony to show off another new IP (maybe that fps from SS and show Uncharted 4 for the first time which will steal a huge amount of thunder. Global launch for September/October. (U4 won't come till summer/holiday14)