I would say hit up Borderlands 1, it was a g-r-e-a-t game. Even if you can't find others play with at this time it was a fun single player romp (for me at least) and goes buy pretty quickly if you don't have any DLC.
I really want to play Aragorn's Quest, but haven't found it any where cheap enough to buy yet! Heh, I've become a real CAG for this generation (can't see any reason to pay full price anymore). If you do play that one I'd love to hear what you think about it.
But finishing up FFIX would be a smart move as well. That would clear it out of your backlog which would be nice... I should do that with XII, I'm very close to the end but haven't made that final push (it's been a long multi-year labor of love).