Too many games to choose from.

[Veknoid_Outcast]

Good choices!

First of all, all three are great. I highly recommend you play all three eventually.

I would start with 999 or Dark Souls, since both have two sequels. Those will both take a lot of time, though. If you want to get all the endings in 999 - and you DO want to get all the endings - it could take as many as 20 hours.