Do you prefer realistic games or artistic games?

[Reasonable]

I like both but prefer artistic unless the game really needs to evoke a more 'realistic feel' to suit its aims.

Just like films though all games require artistic design (not to be confused with being 'Art') so its more about making the right choice. I think comparing the look of say Team Fortress with Day of Defeat gives a nice view on how the appropriate style works wonders for a game.

I also love games like Ico and Okami which really use their art design as part of the game rather than a backdrop - for example Gears of Wars looks great and the 'destroyed beauty' concept is neat but its more of a backdrop than anything else.