I love the Bravely Default series. They are class-based like FF3 or FF5, but (most of them) have narratives that are as strong as FF4 or even FF6. You'll level up multiple jobs on each character, borrowing skills and passives from each to make cool builds, or there might be some fights where you change jobs that are better at defeating certain bosses.
Of the three, Bravely Second is by far the best, but it is a direct sequal to Bravely Deault so you should play that first. Don't get confused: Bravely Default is the first game, Bravely Second is the sequel, and Bravely Default 2 is a completely different narrative in a completely different world with no link to the other two. Think of Bravely Default and Bravely Second as FF4 and FF4: The After Years while Bravely Default 2 is FF5. Quick overview of their differences:
- Bravely Default: very good game, difficulty is pretty moderate, although there are some endgame superbosses that are insanely difficult unless you abuse the Hasten World + Stillness combo which lets you auto-battle everything in the game. The narrative is alright, and it gets a little weak towards the end.
- Bravely Second: absolute masterpiece. It took everything the first game did and made everything better. I honestly believe that, maybe outside of a little too much dialogue, this game has no weaknesses. The character development is incredible and the narrative is genuinely unique and clever. There's even more classes than there were in the first game, with some being removed and a bunch of new ones being added. The OP combo from the first game was removed so endgame bosses are actually challenging (though there are still ways to break the game if you don't mind grinding stat-boosting items). There's also a TON of side content, maybe almost as much as there is main game, and all of the sideplots are bespoke quests with their own well-developed narratives. This game rocks, and I really think all RPG fans need to play it, but you do have to play Bravely Default first or you will be lost in some places.
- Bravely Default 2: this is the weakest of the three games but it's still worth playing. Compared to the other two games, the characters are really underdeveloped and the plot isn't particularly interesting. There are some significant changes to the game which I think makes it mechanically worse than the other two. In the first two games, you have random encounters, but you can adjust the frequency of them (and even turn them off completely if you don't want to fight). In BD2, there are no more random encounters but instead enemy models roam the map and if you touch them, you go into a battle. You can outrun some enemies to avoid them but it's more tedious if you're done grinding and just want to explore and get missed chests. The battle chain system from the first two games is also gone, making grinding a chore compared to the first two games. For difficulty, the early game is absurdly difficult (due to some completely OP bosses) and then the difficulty falls off by the end of the game.
For pacing, Bravely Default moves at a pretty good pace but can slow down at the end (just keep pushing through though, it's worth it). Bravely Second's completion time will vary depending on how much of the side stuff you want to do because there is a LOT of it and it's all very good. I think my mostly-completionist playthrough was over 100 hours. Bravely Second is more like the first; it also slows down at the end but is much more obnoxious about it.
Octopath 1 and 2 were done by the same developers but they're not like that Bravely Default series at all.