1. Final Fantasy 9
My personal favourite FF and one of the all time classics. Its combat is on the slower end (the ATB gauges fill very slowly compared to others in the series) but it has my favourite literally everything else. Lovable characters, a beautiful story and my favourite OST of any game in the series. i think it's the ideal jrpg, so I really don't have a lot to sell here aside from just saying that. it's a throwback to classic FF after 6/7/8 made substantial deviations in art direction, so playing it before those maybe makes you miss out on that development throughline, but it's nothing that can't be fixed by just playing one of those. as such,
if you liked this one, I recommend playing Final Fantasy 6 or 7. (6 being my second favourite in the series)
2. Valkyrie Profile (PS1)
There's two versions of this one, ps1 and psp (with the subtitle Lenneth). play the ps1 version. the psp one is based on the orignal JP version and is missing improvements made to the eng release of the game. there's some new cutscenes in Lenneth but they aren't worth the rest of the experience being lesser.
disclaimer aside, this is another of my all time favourites, but it's also very different from any other game I've mentioned in this longass post, so I think it's a good experimental game too. It's turn based, but your party is assigned to the face buttons on your controller and all take their turn simultaneously. you use different button combinations to create combos using your characters, and every character's moveset is unique which leads to a ton of possible party formats. there's really no other game with combat like it. beautiful spritework, bangin soundtrack.
as for the caveats: mostly minor I'd say, but to get the true ending you FOR SURE need to use a guide. do not believe anyone who says they didn't.
I used one, and this is a very strong contender for my favourite game. the true ending requires you to do some stuff you'd absolutely never think to do under any circumstance.
the eng voice acting is
cheesy as all hell which is something I personally do not consider a fault, but some people might.
if you like this one, I recommend immediately moving on to Valkyrie Profile 2. there are no substitutes (though Indivisible tried)
3. Octopath Traveler 2
The most Recently Released game on this list. you do not need to play 1 first, they aren't connected like that. 2's basically just a substantial improvement on 1 in all regards (imo) so if you play 1 afterwards, it might feel lacking. it's a traditional turn based game, but the "gimmick" is you've got 8 playable characters who can all interact with NPCs a different way. though some of these have the same function (such as Challenge and Ambush), they're separated by the day/night cycle. so during the day you may Inquire or Guide, but at night you'd use different characters to either Bribe or Befriend. doing so can get you items from most npcs you interact with, some of them being very strong weapons you can get early as a result. there's a whole lot going on with it, but in practice it's very simple. it's got a fun class system, a soundtrack that I would consider maybe the best of all time (seriously) and is kind of a big love letter to the genre entirely. as a result I think it's fantastic as both an entry point and an enthusiast game, certainly one of my favourites in recent years. the character's stories are also all just very good, characters like Castti and Oswald really stuck with me, and
Oswald's theme transitioning into the boss theme quite literally brought tears to my eyes on a couple occasions. i cannot overstate how good the OST is, and it really isn't the same unless you hear it ingame due to how it's used. just trust me.
if you like this one, i recommend playing anything that has a class/job system. Final Fantasy 5, Bravely Default, things of that nature. but if you want to try something a bit different, then..
4. Tactics Ogre: Let Us Cling Together
The SRPG entry on this list. idk if people really get finnicky about the definitions; I always kind of just put these and jrpgs together in the same little soup and as such I'm picking this one. there are several versions of this game, including Reborn, the most recent one, and there's a bunch of differences between them. instead of getting lost in the weeds I can break it down pretty easily for you: all of them are excellent, so the answer is "whichever one is easiest for you to get your hands on". I played the PSP version initially and that's the one that cemented it in my favourites catalogue, so don't think you're missing out if you can't grab Reborn. anyway, LUCT is a grid based tactical fantasy rpg with a large variety of classes to play with, and one of the most mature (in the classical sense, not blood and gore and edge) stories in the medium. choices you make alter it drastically and there are very, very few characters who are Just Evil. the enemy general using the generic Soldier sprite you just killed was Marius Renholdt, third son of his family, and the circumstances that brought you into conflict are tragic, but for the sake of your ideals you must continue.
the main downside is that there are a LOT of characters you can miss out on without doing some very specific things, and as such I'd say it's worth considering looking at a recruitment guide. the drawback to THAT however is it can also spoil you on who joins. consider what matters more to you and make your choice, though I think ultimately you'll get more out of the game (and the writing) if you do recruit as many characters as you can.
if you like this, I recommend playing Final Fantasy Tactics or Devil Survivor: Overclocked. FFT and TO have so many similarities that there's no way you won't like it. DSO is a bit different, but it's a Shin Megami Tensei SRPG with similar combat, so I think it's worth checking out especially if you DO play SMT4 like you were thinking about.
5. Shadow Hearts
a cult classic, horror themed jrpg. horror
themed, since it isn't actually scary or anything. but the enemies and environments are all supernatural/cosmic or folkloreish in some sense. combat's turn based, but every action you take (including using items) has a timing component. there's a little ring that appears onscreen with a spinning arrow. if you stop the arrow in the correct spot, you'll land a hit/use an item/skill etc. if you miss, you miss, and if you land it in the very small critical area you'll have a much increased effect on anything you do. bit of a dark horse pick but the definition of a flawed gem, I think there's a lot to love in spite of some of its oddities. it's not really the Best at any one thing it does, but there's not a lot like it.
just listen to that battle theme. I also recommend it because its direct sequel, Shadow Hearts: Covenant.. well it's a direct sequel. you kind of need both for the full effect, and Covenant is a fantastic game.
if you like this, I recommend Shadow Hearts: Covenant, obviously. it improves on pretty much everything presented here. please note, however, that Covenant picks up 6 months after Shadow Hearts'
BAD ending. get whichever ending you want/end up with, but i'm letting you know for continuity's sake.