3. Ico (2001)
Before the recent explosion of indie games such as Flower and Braid, there was Ico. Ico became the definitive go-to title for proponents of the once-absurd hypothesis that video games could be art. To gamers, of course, their hobby had been art for a while. Whereas Mario and Metal Gear come with all sorts of baggage for outside observers (too colorful, too many nuclear robots), though, Ico makes for a more presentable poster child, right down to its famous cover art which you might want to tell that snobbish uncle of yours was
influenced by the work of painter Giorgio de Chirico. With art games becoming increasingly prominent (witness
Jonathan Blow's The Witness at the Playstation Meeting), Ico still stands as the strongest representative of the genre. The influence of its minimalist design and alien atmosphere can be seen in recent tiles such as Limbo and Journey (perhaps even Portal), although trivia fans might want to note that these elements were first seen in 1992's Another World (Out Of This World in the US), which was itself
a huge influence on Ico's designer, Fumito Ueda.