Revelations: Persona is the first game in the Persona series, which is a spin-off from the Shin Megami Tensei series, and was first published by Atlus for the PlayStation in 1996. It was actually the first game in the entire Megami Tensei series to be officially released in the West.
Kyuuyaku Megami Tensei (aka Megami Tensei: The Old Testament), is an enhanced remake of the first two Megami Tensei games that were originally released on the Nintendo Famicom. It was published in Japan for the Super Famicom in 1995.
Like most of the early Megami Tensei games these two titles weren’t released in the West due to them having controversial content based on religious and occult themes. Thankfully, though, they were liked enough by gamers to be given fan translations into English, and this SNES re-release was first fan-translated in 2014. It has also been fan translated into Spanish.
Shin Megami Tensei If… is a spin-off from the main Shin Megami Tensei series that is smaller and more confined than previous games. It was developed and published by Atlus in 1994.
This time the story is set in a school where a bullied pupil tries to summon demons in the gym, to deal with his harassers, only to wind-up being possessed by them and threatening to destroy the world. You play a group of schoolkids who team-up to try to stop him.
Shin Megami Tensei II is the direct sequel to Shin Megami Tensei and was first published in Japan in 1994 by Atlus.
While the basic gameplay is essentially the same as before, with tile-based movement and first-person combat sections, overhead city map sections, and magic, occult and religious themes, the developers deliberately chose not to connect this sequel directly to its predecessor, so story-wise it is somewhat different, being set in the far-flung future.
This cult Japanese Role Playing Game was originally released for the Super Nintendo in 1992 in Japan. It was developed by Atlus and is the third game in the Megami Tensei series, and the first in the central Shin Megami Tensei series.
The game mixes elements of philosophy, occultism, science fiction, religion, and role-playing in a somewhat unique way. It remained untranslated into English for a decade, because of its controversial content and Nintendo‘s strict policy guidelines. It wasn’t until 2002, and an unofficial fan translation patch by team Aeon Genesis, that the original SNES release received an English translation. An official English translation was eventually released on iOS in 2014 by Atlus.
The second game in the Megami Tensei series was developed by Atlus and published for the Nintendo Famicom by Namco in 1990. It’s another Japan-only RPG featuring demon-summoning and turn-based combat and is considered by many to be much better than the first game.