This is a bit out of order, especially since both of these predate Naruto by quite a bit. (I ran out of space using the days of the month, so I've paired a couple that are linked together to the same entry).
I rented Legend of Legaia from blockbuster when I was a preteen and ended up buying Legend of Dragoon because I dumbly assumed it was similar. (It actually took ages for me to find a copy of Legend of Legaia, but I love it so much it was worth the wait.) I've replayed both multiple times. I'm not so good at the addition system, but I am very good at Legaia's system because once you put the combos in once, you have it forever (except miracle arts).
Neither of them have much of a fanfic presence, but what little is there, is good. It's a shame that most of the archives I read on are dead and also that Lady Tempest's site with it hadn't been preserved. (I only managed to access it once and there was only one fic, but it left a mark on me. It made me realize that romance was an option when it came to slash for the first time.)
I've some half-written drafts in my fic folder, about two dozen plot bunnies and various other day dreams that never saw the light of day.
Regardless, I love both of these games and their fandoms and I hope they get a revival in the near future. (but this I doubt)
Legaia is a small party, Vahn, Noa and Gala. Ages are... ??? I assume Vahn's at least 18, but he might be younger. Gala's.. Gala. There actually isn't any slash potential there except with Gaza? And Gi, who is a boss for a chapter. But also it gets a bit creepy because they're at least a decade older than Vahn. The seru are the best/worse part of it, I spent so much time hunting down the spells I needed.
Noa is a treasure and I love her. From the wolf-mom to the dancing queen to accidentally stealing stuff.
When it comes to LoD, I love almost everyone as well. Dart is a hilarious ball of angst and sadness and was clearly wandering one of the other continents judging by how easy they found out about the black monster in-game. Only one of those stories was royalty only and it didn't even tell much. Also I have to wonder how much of his personality/history was distorted when he reunited with Shana, because he is not the lone wolf type.
I could go on and on about my dislike for Shana, but I am an adult and I will not.
Rose is awesome. Lavitz is <3. Albert is also cool, same with Meru. Miranda is the bitch I aspire to be. Everyone else I could take or leave. Lloyd is best anti-hero. He thought he was doing good, he was not.
(No recs, sadly, but I have written for both).