A good game, especially an RPG, captivates the player, immerses them in the world's atmosphere... makes one lose the notion of real world time when you play it.

For that tho happen, these are a must:

1. CONCEPT

- multi-choice, non-linear story/stories = Replayability

- complex characters with deep personalities (options for persuade, romance, influence system, allies etc.) = again Replayability

- detailed character creation/customization (avoid gender locks!) = Replayability

- logical, practical classes/skill trees

- open world, yes, as long as its 'openness' makes sense and doesn't get tiresome

- full voice acting, main char included

2. GAMEPLAY

- easy, intuititve controls

- customizable, non-shifting camera (some prefer 3D, others isometric etc.)

- logical difficulty levels

- good map, detailing quest objectives

- pleasant interface

- grinding should not be a chore; instead, a real challenge in order to obtain a level for a quest, or a title...

- avoid inventory junk...

3. OTHER

- up-to-date graphics which don't torment the eye with "spectacular effects"; keep things simple, yet beautiful...

- nice soundtrack, music

- optional crafting

- minigames

- help/manual/tips/tutorials

Good luck in making great RPG games!

Personal tastes are subjective and debatable, of course.

Objectively speaking now, let's consider these aspects that make a truly unique and mature game experience:

1. FULL VOICE ACTING (important base for any characters' personality)

Notable: Gothic series, Dragon Age 2, Mass Effect series

Winner: Mass Effect series

2. CHARACTERS (memorability, immersion, personality, emotion, romance etc)

Notable: Dragon Age series, KOTOR series, Mass Effect series

Winner: Mass Effect series (almost tied with KOTOR)

3. CONTROLS, MOVEMENT, ORIENTATION (inspired, logical, choreographic combat)

Notable: Gothic series, KOTOR series, Jade Empire, Kingdoms of Amalur Reckoning, Mass Effect series

Winner: KoAR (almost tied with ME)

4. DIVERSIFIED STORY (possible multi-story; attractive narrative, moral choices, alternate paths, different endings etc.)

Notable: Gothic series, KOTOR series, Vampire the Masquerade Bloodlines, Jade Empire, Mass Effect series

Winner: KOTOR series

5. LOGICAL DIFFICULTY (building main character makes a real difference in fights; same goes for equipment)

Notable: Gothic series, KOTOR series, Jade Empire, Mass Effect series

Winner: Gothic series

6. VISUALS AND GRAPHICS

Notable: KoAR, Mass Effect series

Winner: Mass Effect series (almost tied with KoAR)

...............................................................................................

Overall winner: Mass Effect series. This game really draws a standard for the future rpg games.

Conclusion: There are games of the past and games of the future. Games of the past didn't care much about the Person itself (gamer, main char, npcs etc.), whihc means: personality, dialogues, philosophy of life, emotion, romance etc.

Games of the past insisted on graphics, gore, "dark" something, tons of eye strenuous effects, killing. There comes an age when you grow up, evolve and, naturally, leave such games behind you.

Games of the future will come to care more and more about the Person and Emotion above combat and action. Not that action will dissapear, instead will have its place, one well behind the first one of building a Personality and Relations...

That's one reason why some people prefer a good Visual Novel to many so-called "rpg games"...

Meditate and Have Fun!