Does it allow for a wide variety of ways to build and customize your character(s)? Can your experience change based on how you develop said character and the choices made throughout? If combat is more traditional, does it have a lot of strategic and tactical depth? If it's more action-based, then does it do a good job combining the best of two worlds together? Are missions/quests/levels/dungeons varied and well-designed? If it's exploration-heavy, is the world interesting and inoffensive to coast around in?

Having a good story and/or cast of characters is nice and all, but few RPGs actually pull either off well enough. Bethesda's games are NOT among those lucky few.

What things turn me off? Combat-heavy RPGs with horrible combat. Terribly-balanced RPGs where only one or a few options are even remotely feasible to succeed in the game. RPGs that are grind heavy and/or have excessively slow pace are also not my cup of tea.

Defining unique characters you create in seperate playthroughs.

World to explore.

Open ended quests and such.

Many choices to end a quest and lots of dialogue.

- closes hit is Beth games.

Pretty much this.

The "likes" in particular. I'd like to add "moddable" to that list too.

+ open world
+ much to explore
+ character creation
+ immersive
+ atmospheric (like Vampires the Masquerade)
+ good story with believable npcs
+ different hairstyles for men than short or shaved.

- unrealistic romantic relationships
- stereotypical character personalities (that's only ok if it's meant to be funny)
- male player characters that look like body builders
- female player characters with 90DD
- player characters with too much of a badass attitude (it seams that in western RPGs the player character always has to be a badass without real feelings?)

The thing I want most out of an RPG, and most infrequently get, is branching quest design with multiple resolutions. I want to be given choices in how to resolve problems that reflect my character. If I can think of another way to deal with a situation, I want the game to support that. I also want good writing, interesting characters, and an original story.

For replay value, I want a robust class system, or at least the ability to create different kinds of characters so I can experience the game in different ways. I want to be able to play as a smooth-talking scoundrel, a heavy-handed oaf who just blunders in swinging his sword, or a silent assassin who stalks his prey like a cat.

An open world is a huge benefit, preferably with healthy population of NCPs and a lot of sights to see.

I just finished playing through the Main Quest of Fable 3 yesterday and was quite disappointed with how all the main characters disappeared. Now I am king of a land of 6.5 million emotionless drunkards; there's nothing to do but 'be evil' or 'go upstairs'. Perhaps I should've left side-quests for me to complete...

Gameplay comes first for me. Story comes a close second.