I'd love to see Alundra come back, but I'd want it in 2D and I'm not sure that's their speciality. I would also like to see more Dark Cloud, but I think that would need a more drastic reboot rather than a remake. I would also love to see Ico get a fresh lick of paint, but it's not really essential as it's a minimalist game so the basic visuals suit it well enough.
I voted for the Resistance trilogy. I love those games and Sony has a real gap in its catalogue with FPSs so that seems like a pretty good series to update and give another chance. Especially if they put the same care and attention towards it as they did the Uncharted trilogy.