As others have said, games are an art form much like film, but it's just where you classify individual movies or games. Someone said "High Art vs. Low Art", while I also like the "Good Art vs. Bad Art" term. The difference in art in games is like the difference in art in films: arthouse films, Citizen Kane, The Godfather trilogy, Gone With The Wind, and many other movies that will be remembered for their excellent quality or their message decades from now are Good Art in movies. Likewise, in games, it should take a high standard in quality of craftsmanship and/or the ability to present its message through the medium in order to gain "Good Art" or "High Art" status. And I'm not talking about mere graphical prettiness, I mean the overall production: gameplay mechanics, all aspects of aesthetics (graphics PLUS music, color scheme, atmosphere, etc), story and presentation of the story in the game, and other factors. This would at least apply for games starting in the 16-bit generation when such things were becoming easier to do within the game itself rather than relying on other media or text in walls or cryptic snippets. For older games, the "Good Art" ones would probably be those whose quality and/or innovation helped us to reach that point.
I would say, though, that there would be surprisingly few games in each generation that would fall under that category.
As for "Bad Art" or "Low Art", that's pretty much everything else: the games made solely for entertainment value or money that just follow along and don't bring anything new or inspiring to the table, and the games that do try to offer a message but fail to really make the presentation of that message ring true or feel unique or special in some way. You know, the stuff where you just don't get it or it hits you over the head like a ton of bricks every five minutes ad nauseam. In other words, about 90% of both the games and film industry.
Now, if games that are "Good Art" get the recognition they deserve, awesome. As others have mentioned, it helps pave the way for games to explore new ways in which to expand gaming as "Good Art" and also provide an entertaining experience for the consumer.
The problem arises when you get too many gamers who can't seem to tell the difference between "Good Art" and "Bad Art" and try to justify stupid things in gaming in the name of "artistic merit" when there really is no artistic merit to them whatsoever. Sorry guys, decapitating an alien in Halo Reach or watching the boobies bounce in the latest DOA installment isn't "Good Art" and it would make us look incredibly stupid to try to defend those things as such. While games are art, we do have to remember that within every art form there is a very wide range of quality, and something being art in itself does not automatically mean that it should have been created. Anyone can create an abomination in the name of their field, whether it be art, science, philosophy, politics, you name it, and we should kinda try to avoid that and call them out when we see them.