High quality storytelling/Plot
High quality originality/innovation
High Quality gameplay

Gameplay (for obvious reasons)
Storytelling (games can have magnificient storytelling, even if the stories aren't all that great, and I love games with good storytelling)
Visuals (If by graphics you mean technical prowess, then replace this point with something else. A greatlooking game doesn't have to be technologically advanced at all though.)

Above all comes immersion though, but I can't have immersion if any of the above are subpar.

Gameplay, value and originality.
But if pardon me, I'll say great games have greater features than any of these

High Quality gameplay
High quality storytelling
High replay value

Kind of depends on the genre. Sometimes I'd go for the plot, but generally, I'd choose these three:

High Quality gameplay

High replay value (Flexibility/Content/etc.)

High quality music

gameplay
replay
originality

I like cinematic games, hence

Gameplay
Storytellign
Graphics

In that order, please.