Why / Why not:
Valkyria Chronicles: Tactical RPG with Shooter element, excellent story and fantastic art: GET IT! GET IT! GET IT!
Infamous: I personally hate sandbox game, but since you've listed Saint Row-ish game, this one is pretty good, be warn that while it might have replay value the game appears to only last around 10 hours, so if you're expecting 30-40 hrs GTA-ish game then you'll probably come off piss, rent and see if you like it first.
Heavy Rain: Its all but confirm late this year and looks very promising so far, as this is one of the reason you bought a PS3 I'd save some money for this, wait for the review though, the track record of the developer is not stellar and the game has waaaaay to many possible way of being bad considering its a relatively 'first' step into the genre and gameplay style.
Uncharted 2: The quality of the first game and Naught Dog's pedigree speak for themself, the sequal looks great, we've been promised 3 player co-op and there's also multiplayer-versus, but the meat of the game is the fantastic single player story which will not doubt deliver.
White Knight Chronicles: I'll admit, I'm hoping you get this game (if its release in PAL this year) so that I can game with you online :D, I'm getting this for this more for the online mode tbh and I'd love to have another playing partner, the gameplay feel more like a western game than a JRPG, probably feels like a 'lite mmo'
MGS4: Ok, you've heard all the good things about this from every sony fan/fanboy under the sun? Here's some criticism and why its currently on my shelf instead of in my PS3: The VERY VERY VERY annoying install.
MGS4 had some great action scene with fantastic eye-candy, not only are they fun to replay, but its just plain cool to show them to friends, the cut scene really are good (if cheesy) and combined with the gameplay are visually impressive, the only problem? Each chapter require you to re-install the game AGAIN which takes around 5 minute, worst, the current install over-write the previous one.
So if I want to load up the bike chase scene and skip and play the snow stage before starting a new game, I'll have to sit through 3 damn install that has me itching to throw the controller through the lcd.
I've heard the multiplayer is interesting but I bought the game for the single player and never touched it. I'd still buy in on retrospective but I have a kind budget and like collecting games.
Good luck on your purchase!
