So who is an art director and what does he do !?
An art director is generally an artist that has been with his/her game company for a longer period of time ( generally 3 / 4 years) and has proven it's worth. That artist that then becomes the Art director get's the leading role in the development of art within the game.
this means that every asset need's to go past this guy and needs to be approved as it's his job to ensure consistency in the style. Together with the lead director and sometimes animators the art director decides on a style and makes sure all the artists stick with this. Another important thing the Art director does is setting time limits for each asset, poly/texture limits. These are very important things as the end product needs to run smooth and blend in with each other where other elements might have to jump out a little.
Everything fit's together in the heavy stylized ( and awesome) game Alice Madness returns.
I think to be an Art director you need to be creative. Beside the fact you need to know what you're talking about you should know the industry, look around in different area's ( movies, comics, paintings etc) and be able to come up with different styles before anything is set in stone. This is all important as you have a leading role over artist that do happen to know what they're talking about, so in order to correct or help them you should be at least 2 steps ahead if not more.
No such thing as too much information !!!
The art direction in Games is almost the same as that in other medium except for the fact your now stuck with tri and texture budgets. Also the fact that the player can often move freely and is less on a "rail" than when it comes to movies could make it a bit more demanding. But overall the idea is still the same due to both directors making sure the scene's look consistent with the original idea's within a timed work environment.
What is required of an art director ?
An art director needs several qualities. He needs to be able and fill a manager role. Set reasonable deadlines that are achievable for the artist but at the same time keep them sharp while making sure the assets get delivered on time. He needs a good artistic judgment considering every asset needs to pass him before being put in the game, he needs to be able and motivate and/ or inspire the artists while at other times put them to work and tell them off and then the last one probably the most important be able and communicate with the team. If he can't spread his idea's or isn't able to tell why these models are too high poly etc artist might swim in the deep and start getting idea's of their own slowing the production down costing a company a lot of money.
The art director is a very important part of production and should be chosen carefully.
A few games where i found the art style were really good are:
Prince of Persia
I'm a big fan of cell shading though it's easily overdone. I think in Prince of persia they have done a GREAT job with this.
Final fantasy 9
Final fantasy 9 has a really nice art style when it comes to urban environment. I like it in general but the details make it really feel cozy and come to life.