So those are 10 popular ones,you have a different one il add it.
My vote is for resistance: fall of man.first ps3 game i got,first game i played online,great graphics,campaign,and best custom game preferences and clan system of any game..

Since I am devout PS3 player and "fan" this is rally hard but I think I'll break it down this way:
Equally my favorites:
1. Infamous (all of them), Resistance (all of them), Ratchet & Clank (all of them), Uncharted (all of them).
2. Metal Gear Solid 4, Heavy Rain, Killzone (all of them), Sly (Cooper; new one coming out), God of War (all of them), Disgaea (all of them), Valkyria Chronicles. SOCOM (all of them), Warhawk
3. Gran Turismo 5 (& others), Yakuza (all of them),

By all of them or saying others, I meant I like each games from that particular series.
Each offer something different and most of those vary in gameplay. 1-3 is ordered in how much I like them. 1 being most liked, it was tough to decide since I love each and every one of those games.

UserMike : lol,thats most of the main exclusives.so then you must be intending to get the next resistance game,you know the online demos on the store?its very good.

thenumberone : To be honest there are 1-3 games that I mentioned that I don't currently own but have tried most via in store or demo. I did post my PS3 game collection in the other thread, and in my post layout there is my PSN trophy card. Also Resistance 3 does look like another game that's loads of fun. PS. anyone own Warhawk?

UserMike : i have that but i dont play it anymore,i play battlefield 1943.its similar but more realistic.

I would have to say the Ratchet and Clank Future titles are my favorites out of these choices.

My favorite isn't on this list =|

Uncharted 2: Honor Among Theives was MY favorite.

1) Uncharted 2 - This is the type of game I've wanted since I was a kid. Now that it's on the PS3, I have it!

2) Metal Gear Solid 4 - I am a huge MGS fan, so of course this is a sentimental favorite

3) Ratchet and Clank Future - Again, huge R&C fan, so again, sentimental favorite.

4) Heavy Rain - Anyone who says this is a bad game probably only likes games like Halo.

5) Little Big Planet - Seriously, it's a platformer, you customize a LOT. It's open ended. I don't know who can't like it.

How could you forget God of War?!?! That would be my top favourite. 
Although I also own GT5 and Ratchet and Clank: Crack in time (or something like that) 
And I very much enjoyed those 2 as well.

joebab : Ratchet and Clank Future: A Crack in Time is my favorite Ratchet and Clank game next to Going Commando.

joebab :

I can't speak for him, but I absolutely dislike God of War. =/

It's one series I wasn't a fan of at any point, along with CoD.

I don't doubt that some people think it's good. Good for them, I just see those two series as vastly overrated. Like Halo.

I'll have to go with Ratchet and Clank. [= That's my favorite out of those choices, and one of my favorite video game series EVER. 

legacyme3 :
joebab :
Iv added the ones you mentiond.
Little big planet i think is awesome.
God of war,great graphics,never really liked it though.
And uncharted i never thought was great but all 3 of those are some of the most popular ps3 games.

I had a feeling ratchet and clank would be popular.

Uncharted is just the best game ever made!

God of War is my favorite. Something about the story-line just really got to me. I've always enjoyed the classic Greek mythologies, and a game where you can not only live them, but CHANGE them is just fantastic. Not only that, but Kratos is literally the strongest character I've ever seen in anything . . . .ever. It makes sense considering his name means, "power" but gosh darn. He could probably knock out the Hulk in a fist fight. He completely destroys Hercules, who is like, the friggin' pinnacle of strength in mythology. I can't even describe with words how powerful he is. You'd have to play through God of War 3, specifically the fight with Cronos, to understand.
God of War isn't really my favorite to play, that would be Uncharted 2. It's game-play, puzzles, and plat-forming, along with it's incredible graphics make it the most fun.

Little Big Planet is the best platformer on the system, and the best exclusive on the system.

alexanyways : i thought it looked like a lame babys game,i only bought it to shut my friend up.who'da known it was so good.

thenumberone : Just because it looks childish doesn't mean it is only for children. That's what My Little Pony taught me.

alexanyways : i admit it,its an awesome game,i love it,theres NO game like it.and thats a good feature of an exclusive:to be unique.
Oh,and i lol'd at the end of your comment.

MGS4 was the bomb. I absolutely loved that game. It was just so fun for me.

Holla everyone!

I didn't play much of the titles mentioned, but I'd say my fav is LittleBigPlanet ... the uncharted titles are also very good, but lbp2 got me for a long long period of time. That doesn't happen really often with the games of nowadays (warning: retro-liking-Me speaking')

PeeZe

Bizz