PS1: Xenogears
PS2: Digimon World 4 or Mortal Kombat Shaolin Monks

Tagging because I'll wanna see everyone's lists too.

I do not understand why PS1 is leading this pole.
Look at what the PS2 had:

dot hack 1,2,3,4
dot hack GU Vol 1,2,3,4
Ar tonelico 1,2
Atelier Iris 1,2,3
Dark cloud 1,2
Disgaea 1,2
Dragon Quest 8
Final Fantasy 10, 10-2, 12
Front mission 4,5
Grandia 1,2,3
kingdom hearts 1,2
Mana Khemia 1,2
Okage shadow king
Okami
Shadow hearts 1,2,3
SMT persona 3,4
Suikoden 3,4,5
wild arms 3,4,5
Xenosaga 1,2,3

and tons more.

The PS1 obviously

PS1;
FF7,8,9
Grandia
Alundra
Parasite Eve 1 and 2
Suikoden 2
Breath of Fire 3 and 4
Xenogears
Persona 2 dualogy (Play persona 1 on PSP)
Dragon Quest VII
Wild Arms

PS2:
Xenosaga trilogy
Persona 3
DQ 8
Shadow Hearts Covenant
FFXII
Grandia 2 and 3
SMT3
SMT Digital Devil Saga 1 and 2
Tales of Abyss
KH

You should remove grandia 1 from your list it came out on Saturn and PS1 , I'm not going to say who has the best JRPg line up since it is subjective , but i will point out that a lot of your listed games originated or  in xenosaga's case had a spiritual succesor on PS1.

LoD, DarkCloud, Rogue Galaxy.