Originally Posted by
Wolf Kanno
Being the purest that I am, my default answer is to basically emulate all six games as most of the releases have some problem or another, or simply change enough to be considered a different experience all together from the original in the case of FFIII and IV. I'll give a more elaborate answer for each though. I will say now that I generally don't like the PSP/mobile ports. Mainly because I strongly dislike the sprite work for all of them. In the case of FFI, II, and IV the sprites feel way too polished and clean for my taste, I generally prefer the more blocky 16-bit sprites. For the V and VI mobile, I don't feel like the sprites mesh well with the overall design of their games. The sprites look too lanky and their color palettes are several shades too bright for the darker and more vibrant background colors that just makes the games visually unappealing to me.
FF Origins is probably the best in terms of staying true to the original in regards to FF I and II. Origins is based on the Wonderswan version and is pretty faithful to the originals though it fixes all of the bugs in FFI making it noticeably easier. Dawn of Souls and the PSP versions both made compromises to the games difficulty in order to fit in some of the new content they added. Due to these games being pretty light on plot, I feel it's better to play versions of them that retain the original difficulty in order to get some entertainment value out of them. If you're more plot/character focused for JRPGs though and simply want to play these games for completion sake, then any of the newer versions will work cause the eased difficulty will make getting through the games much faster.
For FFIII, it's the same deal. If you want to the play the true experience, I recommend just getting an NES emulator and play the original. The higher difficulty and original game design format is noticeably different from the 3D Remake. The 3D Remake had to make concessions from the original in order to work on the DS it was initially designed for and despite being ported to better hardware, SE made no attempt to restore any of it. The other issue is that Job System was retooled in the remake to make it feel closer to FFV, where any class can stay viable until the end, as opposed to the original where you would likely be shifting classes constantly as they grew obsolete. If you're going to do the 3D remake then the Steam version is probably the best due better control options and being rid of the annoying and gimmicky Mog Message sidequest that some of the content is trapped behind in the original DS version.
IV has a a lot of versions. If you want to play the most faithful adaption, play an SNES emulated one with a good translation as the US version has lots of edits while the PS1 port has a lackluster translation. The GBA version is not bad, but find the European version as the Japanese/US versions are buggy. Not to mention the GBA has an inferior graphics/music card so the game looks and sounds off to anyone who has played the original, I was also not a big fan of the addition of the Lunar Trials and and the party switch mechanic, but I've already admitted I'm kind of a purest who is stuck in their old ways. The 3D Remake is a bit of an odd duck. It makes several gameplay changes to give the game more appeal to modern gaming tastes such as the addition of mini-games and more sidequests, as well as a real customization system called the Augment system which replaced the GBA's new party switch feature. What makes this different from previous entries is that they retooled the bosses and enemies to compensate for these new powerful upgrades so the game would retain it's legendary difficulty unlike the FFIII Remake. There are also some added story elements like a few additional cutscenes and the ability to read your party leaders thoughts on the menu screen. It's honestly not a bad way to go, but it does feel different enough from a fan of the original to almost feel like a different game in some ways.
V and VI are probably the hardest on this list because they've had the fewest ports behind FFIII but whereas FFIII has a clear option in my mind, V and VI don't. The issue is that the originals have the superior audio and visual components, whereas the GBA ports have the best translations and in the case with VI, fixes a ton of bugs that made the original game too exploitable and easy. For FFV, you can always split the difference and just emulate the game. The translation is serviceable though lacks some of the charm the new translation has, but thankfully is more respectful and higher quality than the PS1 translation. You also get the classic and superior graphics and sound over the GBA and mobile versions. VI is the one where you're going to have make some concessions. The GAB version plays better than the original and the translation is probably the best out of all the versions I've played though it does change a few lines people prefer in the original, but the graphics feel washed out, and the audio is noticeably different for veterans and considering VI is often argued to have one of the strongest soundtracks in the series, that's a huge detriment. The mobile version has fugly sprite work and the PS1 version has an inferior translation and noticeable load times. So your best bet is to emulate and use a fan translation to get the authentic feel but I kind of feel the fan translation is devoid of real personality for some characters and of course, you'll be playing with all the game breaking bugs still intact. It's your call at that point.