Exactly as the title says. What are the Sony series/games that you want to, but, for whatever reasons (lack of money, not owning the system, laziness, etc.), never got around to trying/buying? List the franchise/games and the reason(s)you want to play it, as well as the reason you haven't yet.
For me, the big ones are LittleBigPlanet, God of War, Gravity Rush, and Wipeout.
I like 2D platformers, and LittleBigPlanet looks charming and fun, but I only got a PS3 semi recently (predominatly for the Kingdom Hearts remasters and Ratchet & Clank), and don't have too many games for it yet.
I like action hack and slashs, and I actually have all 3 numbered games, so I have no particularly good excuse for not having played God of War beyond crippling laziness.
Gravity Rush I actually have a decent excuse for, as I have neither a PS4 nor Vita, but I intend to get a PS4 (eventually), and Gravity Rush will be one of the first games I get for it (after Ratchet & Clank of course).
As for Wipeout, I've only honestly only found out about the franchise very recently, and it looks fun.
Some individual games include Twisted Metal for the PS3 (I played an older TM for the PS1 with my friends a lot, and loved it to bits, but I only got a PS3 recently and don't have extra controllers.), and Jak 1 and 2 (I enjoyed Jak 3, and got it cheap from a used game store).
My original Nintendo thread: http://gamrconnect.vgchartz.com/thread.php?id=218685&page=1