Come on tbone, you already know that :P

I remember Ys being the second biggest JRPG franchise in japan. I'm not sure wether it's in number of installments or sales, and I was unable to retrieve the source. I also assumed FF was bigger than DQ, both in installments and sales.

Based on the sales of these series over the past five years or so within Japan:

Top Tier (Over 6 million Sales)

1. Pokemon
2. Monster Hunter
3. Yokai Watch
4. Dragon Quest

Second Tier (2 to 4 Million

1. Final Fantasy
2. Inazuma Eleven
3. Tales of

Third Tier (0.75 to 1.5 million)

1. Fire Emblem
2. Mario
3. Dark Souls
4. Shin Megami Tensei
5. Persona

Note that the Top Tier besides Yokai Watch all had big games in 2010 not counted here. Dragon Quest would have been second a few years ago, but Monster hunter's move to the 3DS and the birth of Yokai Watch now overshadow it.

The second tier includes shows that Final Fantasy still has strong points despite its relative decline.The FFXIII sequels didn't do as well as X-2 back in the day, but still sold a bunch of units. So did Type 0, FFXIV, and various spinoffs and remakes.

One oddity to note about the third tier is that if I were to treat Persona and Shin Megami Tensei as a single entity, they'd be ahead of Fire Emblem. Speaking of which, Awakening and Fates were both similarly big hits, selling a bit over 0.5 million each. The series hasn't done this well since the SNES.

"Mario" includes both Sticker Star and the Mario & Luigi games.

If im not mistaken, Kingdom Hearts is gigantic there too.I think it is on the top 10 too

Yokai Watch isn't bigger than Dragon Quest bro. Pokemon is probably #1, Dragon Quest (if not tied with Pokemon), then YW, then FF. Once YW sells 4+ Million then we can talk. Ys isn't bigger than any of these. They have more games than other JRPGS but it is by no means bigger than these. The latest game only sold 100K copies there compared to a remake of Dragon Quest VII which is about 1.4M.

But back on topic, Ys, Persona, Monster Hunter, Tales, Mana, come to mind.

According to VGC database http://www.vgchartz.com/gamedb/?page=1&results=200&name=&platform=&minSales=0&publisher=&genre=Role-Playing&sort=JP the undisputed top are of course Pokémon, Dragon Quest, Final Fantasy, Yokai and Monster Hunter (if it is JRPG).

Then there are som old series like Chrono, Mana and SaGa that has sold more than a million per game, as have an old Eidos series: Dragon Warrior. Kingdom Hearts is also over one million, as is also Arc the Lad, Parasite Eve and Inazuma Eleven 2.

Below a million but more than half a million are games like: Xenogears, Seiken Densetsu, Tales of, Mario & Liugi, Earthbound, Star Ocean, Dragons Dogma, Paper Mario, Phantasy Star, Dark Souls and Fire Emblem.

All acording to our sponsor VGC database.

EDIT: Neither Ys, SMT or Persona have had a single game above 0.5 million in Japan according to the database. Is this really true?

Yes, you are right!

Never heard of Ys being that big in Japan ever 

I really knew Seiken Densetsu is the same as Mana. Sorry!

Cant find any good sales figures for Ys. 

SMT + Persona has sold over 4 million in Japan (more than 20 games).

... "In terms of the number of game releases, the Ys series is second only to Final Fantasy as the largest Eastern role-playing game franchise"...

https://en.m.wikipedia.org/wiki/Ys_(series)

https://en.m.wikipedia.org/wiki/List_of_Ys_media