Square has remade FFs I-IV (not just rereleased), some of them multiple times, so I'm sure it's crossed their minds to do the same with their 5th entry.
People cry for a FFVII remake, and I'd not turn my head away from a FFVI one, but of all the FFs left out there I would say V gets me most excited for a remake due to the potential for its wonderful job system. Imagine a FFV with the graphic upgrade that FFIV got and a job system similar to Tactics or even the Dresspheres of X-2. Where instead of just leveling jobs you get AP and can use them to buy abilities or passive traits. Or even a possibility where you can change jobs mid battle. I would definitely shell out for a 3DS or Vita to play that game.
Discuss how awesome this idea is as well as how you would improve the job system in a remake of FFV.