Finished voting and I must say that overall the selected nominees were very good choices. Certainly there is some video game "pop-art" in there as opposed to real artistic endeavour (yes, I'm equating CoD to a painting of a soup can), but for every one of those choices the other nominees in the category were always more worthy options.
Personally, I would have liked to see voters given 4 votes based upon console in general as opposed to only having one choice per genre per console. While this probably would have meant less "artistic" genres such as strategy titles would have received less votes overall, it would have allowed for a better representation of truly artistic titles. You could have had, for example, Silent Hill 2, Ico and SotC all as choices under the PS2 umbrella instead of potentially being played off against each other in the same genre. (I know only SotC was there, but I'm assuming the reason at least Ico wasn't included is because SotC was). Under a 4 votes per console approach, each of these games many would agree are worthy of inclusion could have received a vote if the voter chose as opposed to only one of them getting a vote and the other PS2 votes being "wasted" on, well, anything in the Target or Strategy genres (other than maybe MGS2).
The only notable omissions I found (that I can recall off the top of my head anyway) were the aforementioned Ico and Silent Hill 2. These are two games that (almost) always come up when games are discussed as art so it's odd they didn't make the cut. As said above, I'm guessing Ico didn't make it because it was either Ico or SotC for the spot and SotC won, but I'm really not sure why SH2 was excluded.
Anywho, my biggest personal issue came when I found myself having to choose between a game I considered great and a game I considered good but perhaps better as an artistic achievement. For me this is best exemplified by the choice between Limbo and Mass Effect 2 (Era 5, Xbox 360, Adventure Genre). I love ME2 and consider it one of the best video games of all time, but beyond some intriguing moral choices and the choose your own adventure story I can't say it really strikes me as the best example of game as art. I really like Limbo and consider the instantly memorable visual style and the thought provoking ambiguous setting/story to be a near perfect example of game as art, but as a game it's short, a little repetitive and loses some steam in it's latter half. In the end I chose Limbo, but I could have easily gone either way. Kudos to those arranging this exhibition for not only creating it in the first place but also for making the selection process one that engages the gaming public in further examination of their own hobby.