It seems like the snaps from that site are pretty random...
Although they're in the Goodtools format, the collection is nowhere near complete... alot of times a game will have a screenshot for the (J) [!] version and not the (U) version, or the other way around.. and it doesnt even seem to be consistent in the idea of using the "best" version, as not all of them are [!]... it just seems to be random on which versions there will be screenshots for, and you have to have the EXACT same list of games/versions to have a seamless scroll of games with screenshots...
EDIT: Well after looking I can't for the life of me find another source. So all things considered, it's the best available. Although you'll have to go through and take care of the missing snaps, it's definitely better than working from scratch