cross edge
valkyria chronicles
disgaea 3:abstence of justice
mgs 4
uncharted 1 and 2
ratchet and clank future and new ratchet and clank game
killzone 2
lbp
folklore
genji:days of the blade
super stardust hd
linger in shadows
resistance fall of man
resistance 2
motorstorm 1 and 2
demon souls

Resistance fall of man and Resistance 2 are great games.

I would suggest a rental on MGS4, if you're a MGS fan you have to play it to complete the story.

Here's a snippet talking from another post talking about all the exclusives I've played:

• Uncharted --I hated the Uncharted demo and wrote it off as a bad game for the longest time.  Luckily someone convinced me to give the game a try (and luckily someone else made me pick it back up a year later and actually finish it) since this has been my favorite PS3 game (counting non-exclusives).
• LBP -- I don't like LBP planet and I put some good effort into it.  It's not that it's bad, it's just once you get past the art style it isn't anything special.  The platforming was usually passable and sometimes even bordered on bad, I hated the SIXAXIS controls being on all the time, and just about every user created level I played was garbage.
• Killzone 2 -- I hate hate hate *haaaaate* Killzone 2.  I admit, it has some of the best atmosphere I've ever seen in a game.  It does a wonderful job of making you feel like you're just in the middle of shit but the game itself ranged from horrible to bland and had two of the worst boss fights I've ever played (the one fighting the flying thing on the roof and the whole final boss sequence).  I tried the multiplayer and it just wasn't for me since I'm really not a multiplayer person.  Funny enough, most people say that if you didn't like the game it was because you couldn't get the controls-- I got the controls fine (though I didn't like how they handled cover), I just don't like the game.
• Wipeout HD -- I started downloading the demo last week because someone got me to finally try it and I just phail at the PSN.  I still haven't been able to get it completely downloaded.  XD
• Flower -- I want to try this, I just haven't gotten around to it yet.
• MGS4 -- I tried twice to get into that game and both times I got past the weapons dealer guy and I just couldn't take the game anymore.   It's not for me.
• Resistance: Fall of Man -- I was a little tough on this game in the beginning but after playing it completely through, it's not a horrible game.  It's a good throwback to classic FPS games and I can dig that.  That said, I still don't think it's exactly a good game and if it were released today, it would get completely lossed amongst all the better games.
• Resistsance 2 -- This game took everything I liked about R:FoM and threw it out the window and replaced it with more things I don't like.  This game sucked.
• Ratchet and Clank -- I tried it and for some reason it just didn't grow on me.  I might try it again one day, but not anytime soon.
• Eye of Judgment -- What a fucking terrible game.  The eye works if you're in the perfect area, kind of works if you're in a passable area, and flat out doesn't if you're in any kind of normal living room.  Also, this game couldn't be more unbalanced.  If you go first, you're probably going to win.
• Motorstorm -- Eh, came with my PS3, tried it, went back to Excite Truck.
• Naruto: Ultimate Ninja Storm -- I loved the actual fighting and the art style, I hated the God damn side quests it made you do to progress through the game.  This would have been a great game if it didn't make you do so many pointless redundant side quests.
• Valkyria Chronicles -- I bought this game and played the first few missions, enjoyed it, and then put it down (I have a bad habit of doing that, even with games I like).  I'll pick it up again one of these days.
• Buzz -- I played this last weekend with a few people and I loved it!  My only complaint with it was that when doing the user generated questions the only game mode it did was fastest finger.  Sadly, as much as I liked the game, I'll never buy it.  I don't want to buy all the extra controllers and I rarely have enough people over to take advantage of it.
• Folklore -- Tried the demo and didn't have any want at all to try this game.
• Heavenly Sword -- Just didn't like this game, but I also don't like God of War.
• Lair -- Ahahahaha, haha, ha, haaaaa...
• Demon's Soul -- I'm actually pretty interested in this one, wish I had payed attention to it earlier.

Uncharted 1 for trophies and its good/cheap/good preparation for Uncharted 2
Uncharted 2 (duhhzz)
GT5:P (or full game when it releases) so you can have best of both worlds
LBP
MGS4 (if u like other MGS's)
Valkyria Chronicles (If u like RPG's)
Demon souls when it releases should be good

I second this.

Flower is unlike any other game I've ever played. It's a thing of beauty.

UT3 is actually a decent game not many people talk about. With the addition of the free Titan pack (split screen co-op, trophies etc.) it bumped up from average to quite fun in my opinion.

Resistance: Fall of man
Resistance 2
Uncharted: Drakes Fortune
Uncharted: Among Thieves
Metal Gear Solid 4
Little Big Planet
Motorstorm: Pacific Rift
Valkyria Chronicles
Eternal Sonata (multiplat, but its great game and its better on PS3)
Ratchet and Clank: Tools os Destruccion
Infamous
Folklore

Download:
Pixel Junk Eden
Flower
Super Stardust
Fat Princess
Trine

You're so negative it makes me laugh.

No! Screw that game, it sucks.

• The combat is cool until you get the chick with the bow that completely breaks everything.  She can heal the entire party and kill a strong enemy in a single turn.  Once I got her, nothing was hard.
• The story and music are so-so.
• Fort Fermata is the absolute worst dungeon I've ever even heard of in a game.  Nothing will ever top the bullshit that is that dungeon.  It's not bullshit because it was hard, it really wasn't, it's just bullshit because it is so horribly laid out.
• You get a shit-ton of money within the first hour of the game that can last you through the end of the game probably but you don't get a chance to actually use it until 10-15 hours later.

There were many other gripes I had about this game, but just don't get it.  It sucks.  There are much better choices out there for a 360/PS3 owner.

I'm not going to bother with a full list. It won't help you, with everyone shouting everything.

So all I can do is urge you to get LittleBigPlanet.