For me the real questions are which ones have I redeemed and which ones have I installed. I have several DLC that I redeemed to get it on my PS3 download list before expiration, but I don't get around to downloading and installing them, so I don't know whether or not I actually have the DLC active since it's usually not game data I can see directly from the PS3's menu; I have to load each game and see if the DLC is there.
I don't know if I've installed all the LittleBigPlanet DLC available on my PSN account, for example, unless I decide to boot up the game and cross-reference its in-game menu options with my download list. I don't see any other way to really do it.