ShinyCharizard said:
If you want a great shooter on PS3 that isn't a gunwank game (halfway eliminated Killzone 2 and definately Killzone 3 right off the bat) then I can not recommend Resistance 3 enough.
You also said single player, so I'll focus on it's campaign:
-Excellent story with good characters, it's not predictable and keeps you guessing. The set pieces are well placed and paced and don't absorb the game, there's plenty of depth to the plot and it really sucks you in.
-It has a great aesthetic style and good graphics without any of the obnoxious over-lighting bloom that's starting to plague shooters. (Something I hate, I detest bloom it burns my eyes).
-The gameplay is fun and engaging, there are many weapons and you can carry all of them at once, limited health keeps things tense and exciting and the game is well balanced for it. Every gun has it's own secondary fire mode and you can carry up to 4 kinds of grenade (5 if special edition, wouldn't bother just for extra grenade type, they're rare and not too great). All the weaponry and explosives are fun to use and have unique properties. You have and SMG, a shotgun, a rifle, then more interesting things like X-ray rifles that increase in damage the more you shoot through stuff, the cryogun for freezing and a massive air blast to shatter, fire explosive shotgun secondary fire, the gun that gives everyone in the room ebola, the lightning gun that has a gravity well for secondary, etc. The enemies are challenging and interesting, with a variety of types and functions. I particularly am fond of the Grimm's.
-Environments are fairly open and offer freedom and choice in combat almost all the time, when you're forced into a tight corridor it usually is a very tight corridor which leaves you quite vulnerable and ramps up the tension, it has some great horror elements at points.
-Lots of collectibles to grab, cheats (yes, real cheats, that change the game, such as changing the health system, infinite ammo, giving enemies more powerful weapons, etc) to unlock and some interesting trophies to be done.
-Full campaign co-op both on and offline.
Absolutely a brilliant game and if you want a stellar fps on the PS3 it's probably my favourite on the system.
(Multiplayer is pretty fun too, as is the horde mode DLC)
Oh and: Portal. Portal 2.