Gameplay > graphics anyday. Good writing is also important. You won't see games like Planescape nowadays cause gamers today can't read worth shit.

First off all I want clean and fluid graphics in any game, because I don't want graphic problems to interfere with gameplay. So generally I prefer simple and low-detailed but clean graphics @ 60fps, rather than high-detailed graphics @30fps with jaggies.
Than the level of detail I require depends on the type of game experience. An arcade type of game that doesn't rely on immersion or storytelling can also be quite simple (for example, I'm perfectly fine with NewSuperMarioBrosU graphics).
If you have an immersive game experience like Metroid or Demon's Souls or Metal Gear of course I want graphics to look as good as possible and sound to be as good as possible, still considering in order: 60fps + clean graphics > 30fps more detailed but less clean graphics.

To me, it's just a luxury thing. (in temrs of realism) I think art style is more important.

If the most essentials aspects of a game are OK, decent graphics are enough for me: gorgeous graphics can be a welcome bonus, but they must not subtract dev resources from gameplay.