Since people like to complain about bitch about every game here are unique things I like about each game.
DR1:
>nice, self-contained narrative that builds up to one final resolution and that resolution is really well done, plot and character threads come together for a very satisfying experience, you cant take away from these things even if later games may have refined them a bit, the first time always gets extra credit
SDR2:
>the final confrontation is really interesting, whereas in the first game Junko's offer to betray Naegi was never all that tempting, here you have two sides going at each other with great points, this time Junko created a real dilemma that has no apparent or easy solution until the plot kicks in
DRV3:
>unlike other games where most of the character interactions are left to free time events, meaning any one playthrough is never going to capture everything, here a lot more focus is on the relationships between Saihara, Kaito and Maki, meaning the bond between them feels a lot more genuine and the resulting payoffs when the character drama comes into play feels a lot more earned
>also the finale is by far the most brutal one, total ego death that the survivors try to escape with a collective suicide pact, that's real heavy shit
also, tenko is best girl