"Which kinds of game-related art do you think are more interesting?"
Results so far:
Games are the work of art themselves (6 votes)
Ok, 7 voters are not that much, but there is a point becoming clear to me (specially when I take out my own biased votes): players may want a game to serve as a creative tool, but they will always want it to be a game - not only a tool.
Corvus makes a good point: it´s all about the world that is given to the player. If the atmosphere is right, there will be a good reason for players to join in the creative process. They usually want the setting, the look and feel, the plot, etc., so they can build something on top.