It is certainly a big topic as to weather video games are art, and I'm sure a lot of people here will say that they are.
But sometimes you have to state the obvious for people to see it, so without further adieu, we will examine what a game is made of.
Music: I think almost all people will agree that this is art.
Pictures/graphics: Also art, although a lot of games use stock images.
3D Modelling: Arguably art, I would say it is. You need to be quite creative to be good at this.
Programming/technical aspects: Very debatable, you do need some creativity to program but it is usually not art.
Story: Again, most people will agree that this is art.
Marketing: Not really art.
Design: Probably art. This includes maps, vehicles, sound placement etc.
It is obvious that this is somewhat of an over simplification but I think it sums it up quite well, and even if it doesn't I think it suffices.
So I think what can be drawn is that video games are not art, but a combination of many things. Some of which are art, and some not.
This is not to say video games do not take a lot of talented people to make, and I have some of the utmost respect for people like Martin O'Donnell, Jason Jones, Markus Persson (Notch) and many others.