I was once advised to never get into the “are games art?” discussion, and it’s entirely understandable why. You’d need to define art first, and as a purely subjective thing, art simply can’t be discussed without warranting an endless loop of (often pretentious) debate. It’s really not worth arguing with your friends over.
Personally, for me, I consider something artful if it sets out with the intention to make me think, and succeeds. Of course, even I realise that I’m probably wrong there, because that would exclude works of great technical skill – the Mona Lisa, for instance – that don’t tend to make me think anything more than “Oooh, pretty. I guess.”
Recently, Heavy Rain has also challenged my very loose definition of the subject. Very enjoyable game, no doubt; I lost weeks to the damn thing, and probably a small portion of mental health as well. You see, I had some stuff going on in the real world then, stuff from which even gaming couldn’t provide an escape.
I did a write-up of my thoughts on my Destructoid blog, and surprisingly enough got front-paged. Read it here, while I hit F5 on the stuttering, unwatchable video that will supposedly explain what Icarus is.