Based on Artistic merit, i would have to go with Shadow of the colossus.
A simplistic yet powerful story, featuring sixteen gorgeous beasts in a otherwise empty, and desolate world.
That of which you must kill, but the raw power, and beauty of these colossus makes you feel sad for every single one you take down. That raw emotion makes it (in my eyes) the best work of art in any media i have ever experienced.
Also, I would love to force people who think games are just murder simulators, to sit down, and play shadow of the colossus.
It will most certainly changed their preconceptions that's for sure.