What Ps3 Game Should I Get?

I have about 20 bucks(i know it's not alot.. just read the whole question!) and i wanna get a new ps3 game. if it's not brand new.. i could get a ps3 game used at gamestop for about $18. i bought bioshock 1 today.. and i'm just not feeling it. it's just okay for me. i just don't love it like i have with other games i own. here's a list of games that i own.

Assassin's Creed 2
Uncharted 2
Little Big Planet
Civilizations: Revolutions
Infamous

Kind of a weird group.. I know..
I like first person shooters..
actually i like pretty much anything as long as it's a good game.
thanks for your help!

Answer:

Call of Duty: World at War – This is a fun, fast paced First Person Shooter set in WW2. Probably the best done WW2 game to date, has attack dogs, limbs being blown off, Bayonet attachments. The game is rather noob-friendly, so anyone can be good at it. (Has Spec-Op missions which is like a small 2 player co-op mode)

Socom: Confrontation – Amazing third-person tactical shooter. It is a very tactical team based game, definitely not one that everyone is good at.

Resistance 2 – The sequal to the hit game "Resistance: Fall of Man." Slightly dumbed down single player, but that doesn't make it suck by any means. But the real treat to this game is the online modes, amazingly done Co-Op mode, and 60 player competitive game modes.

Metal Gear Solid 4 – Well, there isn't much to say here, the title should say it all. It is just an all around perfect game when it comes to single player, not many games can contend with it.

Fallout 3 – A First/Third person Shooter/RPG made by the highly acclaimed RPG developers "Bethesda" (Creators of the hit Elder Scrolls series, Morrowind, Oblivion, ect.) It takes place in a post apocalyptic world where people stay in "Vaults" to protect themselves from the harsh enviroment, until one man decides to leave…

LittleBigPlanet – This is a side-scrolling platformer. It has by far the most advanced physics engine to ever hit a game. In LittleBigPlanet you play as a little sack person, which you can dress up and decorate any way you like. For instance I had both a Joker and Sub-Zero costume that I made myself. It also allows you play any level, even story levels with your friends.

It also allows you to create your own levels, for people all over the world to play and rate. It gives you all of the tools the game developers themselves used to make the story levels, so there is virtually no limit to what you can do in LBP.

Naruto (only one for ps3)
Great fighting game, if you dont know what i mean i mean like Dragoon Ball Z, or Soul Caliber etc. but Naruto version. If youl like anime than this is a great buy! The graphics are superb!!! They have developed it so well it actually looks like an anime that you can decide what it does. This game is very fun and not hard to play. Some of the strongest moves are activated just by hitting circle a couple times. But learning to dodge them, block etc. and you super chi moves is where the more depth of the game comes in. So its a quick fun game, which you can come to just pawn people at.