Well, I'd be glad to help in any way I can.
Before anything, though, I'd recommend looking up reviews for the games you're considering before buying them, because you may think something looks really good and it end up being terrible.
First, the games form your list:
Pain: This is literally the first game ever released for PSN. And personally, I hated it. It's basiclally you slingshot characters through different locations and try to hit stuff, and get them hurt. The worlds are filled with sexual innuendo. It does have a LOT of content with all the expansions, and a ton of trophies (some of which are extremely difficult). Overall I didn't like it, though, I thought it was boring, and I didn't like the controls. I'd give it a 2/5, because the innuendo is funny.
Journey: Journey is a true masterpiece. It's an experience (like all Thatgamecompany games). My only problem with it is that it's very short. Regardless, it's a very fun experience, and it does have some replayability, which somewhat makes up for it being short. Essentially, it's a puzzle platformer. There's no fighting, but there are enemies you need to avoid at times. It's a community experience, and you will likely meet other people in the game. For what it is (a beautiful, short, experience), it's great. 4.5/5
Flower: Also from Thatgamecompany, Flower is also a masterpiece, and the first game I played from Thatgamecompany. And it's truly beautiful. I mean, I posted this in the "Most beautiful games" thread because it truly belongs there. You control the wind and collect flower pedals, and it's all about the journey (essentially, you play as flowers that are in the city who wish they could be living free in the fields n' stuff. It sounds silly, but it's really deep and beautiful.) 5/5
Eat Them: This game is just awful. I've only played the demo, but...that's all it takes, you'll see when you play the demo. 0/5
Fat Princess: Fat Princess is a game that I was really excited about before it came out and became really disappointed with after it came out. That being said, I may want to give it a second chance. I didn't like it because it just wasn't as great as it sounded. It's a capture the Flag game, but it just wasn't executed well (from what I remember). The visuals are great, and the gameplay is smooth, but I just didn't like the gameplay. 3/10
Now, here are some games I would recommend:
Highly Recommended:
Plants Vs. Zombies: I seriously got addicted to this game, it's just so good. So much fun, solid gameplay, and enough mini-games, and challenge modes to keep you playing. Really really great game, highly recommended. 5/5
Chances are you've already played PvZ and know it's great already.
Costume Quest: Really really really good RPG from Double Fine. It's a really really really easy game, but that doesn't mean the gameplay isn't awesome, because it is. You play as a brother or sister, who's sibling gets kidnapped by a Goblin during Halloween, when they go trick or treating. There's also an expansion that's really good. Highly recommended. 5/5
OuTLand: There's a lot of side-scrolling platformers on PSN, and a lot of them really suck; OuTLand isn't one of them. It's a really excellent platformer with smooth controls and a smooth combat system, with excellent gameplay. As you progress, you gain new powers and are able to access different areas. There's collectables that have you backtracking. The visuals are really beautiful, and the boss battles are really good. It can be challenging at times, and you'll have to think to figure some things out, but this is not a bad thing. It's also pretty long for a PSN title, which I really like. 5/5 (I honestly can't think of anything bad to say. It's challenging at times, but it's not bad because of this.)
Sam & Max: The Devil's Playhouse (Episodes 1-5): The entire series is free, so it's a give in to get these games. There's 5 episodes, originally a point-and-click adventure game. Really great, funny dialogue. The gameplay is great if you like this sort of game. If nothing else, give 'em a chance. They're free, they have trophies, and they're fun. 4.5/5
Quantum Condundrum: Really excellent game. Definitely worth the money. If you like Portal, you'll undoubtedly like this game. And that's no coincidence, the lead designer from portal worked on it. You control the environment in a very Portal-like physics-y way. There are 4 different dimensions you can change the world into: Fluffy, Heavy, Slow and Reverse-Gravity. They're all really fun to play with and the game in general is just really good. There is some glitching and some annoying issues with staying on couches/tables (like when you think you're on them and you fall off, type things, but it's not significant enough to turn you away from the game.) Highly recommended. 4.5/5
Resident Evil 4 HD: I had never played this game before, and I have to say, this game is amazing. The controls take some getting used to, but that shouldn't be a turn off, because it's worth getting used to them, because this game is excellent. With trophy support. Plus it's a full-length game for about $15. Definitely worth it in my opinion. Highly recommended. 5/5
Worth checking out:
The Walking Dead: I wasn't a fan of the show before I played these games, but they're good. I got the first two episodes for free through PSPlus, though, I don't think they're worth paying for unless they're cheap, but they do have a seasonal pass thing, where it's like 20 bucks and you get all the episodes when they're released (There's 5 episodes, but only 2 are released so far.) 3.5/5
Mega Man 10: If you like Mega Man, check these games out. If not, I dunno, I bought this by accident and ended up really liking it. It's really difficult, though, on any difficulty other than Easy. 4/5
PacMan Championship Edition DX: Also a game I got for free through PSPlus. I probably wouldn't pay for it, but it's worth about $5, I'd say. Great reimagining of the PacMan universe. Really really fun gameplay (I played all the time trying to get the trophies). It's just a really fun game. 4/5
Sideway: Sideway is a pretty cool platformer where you play as a tag (graffiti) and you go along walls. It's a really interesting idea. For some reason it just wasn't good enough for me to justify finishing it, but it's not a bad experience. I also got this through PSPlus, so I can't complain. 3.5/5
Warp: I only played the demo for this, but it's really really good, and I'd like to buy it at some point. I recommend playing the demo as well, to see what you think. I won't rate it because I haven't played the full game.
All of the "PixelJunk" games: Okay, not all of them. Not Eden and not Racers, those games suck. But PixelJunk Monsters is great, both of the PixelJunk Shooter's are good, and Sidescroller isn't bad. Monster especially is great. 3.5/5
Stacking: A game from DoubleFine (the same people who did Costume Quest). This game is about Matryoshka (Russian Stacking) dolls, and the gameplay is really good. I never finished it, though, but it's definitely worth checking out. My friend bought it, and I game-shared with him. 3.5/5
Critter Crunch: A very fun puzzle game with a silly story. 4/5
Hydrophobia: Very cool game. Hard to explain, kind of like Uncharted if Uncharted was created on a much smaller budget and made to be a download. Also if Uncharted was about being locked in a facility with water all over the place. 3.5/5
Age of Booty: I'm not sure if anyone actually plays anymore, but it's a strategy game where you play as a pirate ship and try to collect treasure and sink other ships. It's set-up like a tabletop game (like Settlers of Catan). It's pretty cool, but unless you have people to play with, it gets boring quick. 3/5
Magic Orbz If you like Breakout-style games, you'll like this. Because it's a really good one. With lots of expansions. It's very difficult at times, though. Still, worth checking out. 4/5
Games to stay away from:
Frogger Returns: Truly awful game, and gives Frogger a bad name. -5/5
BloodRayne: Betrayal: The idea isn't bad. You're vampire, you kill people. Simple. Yet this game executes in a really bad. There's parts where you randomly just start hurting, but it doesn't explain (or it does a really poor job of explaining) why. I just didn't like it. 1/5
More to stay away from:
Savage Moon
Geon
The Punisher: No Mercy
FLOCK!
Hope this helps.