Yesnod doesn't sound like a very fun game...
Favorite past game, huh... Good question. The WiiU ain't out yet, so I can't say Brawl... Pretty tough to say.
I could safely claim Shadow of the Colossus as my favorite, though. That game's artstyle was indeed, the definition of art. The sheer epicness of the game rolls TLoZ up into a ball and tosses it aside easy. The music was a ****ing eargasm. And of course, for me, the gameplay was absolutely unforgettable. I've played that game many times (and beat it every time, of course), and thoroughly enjoyed each and every playthrough. Never got sick of the game, and I'll probably go back and play it for the bazillionth time in a few months too.