Gameplay of course, it's part of the reason most of the games I play are really old. I would rank sound next, followed by graphics. But attention does need to be paid to all of them. Graphics is part of gameplay, think of the shot animations in a certain other cricket game, some problems with graphics are to the detriment of the whole game. And audio adds an "experience" of sorts, sound helps you feel like you are playing real Cricket.
So get gameplay great, but if the graphics and sounds are horrible, then there isn't much of a point in having great gameplay. But I do think TAOC is well on the way graphics wise, and I'm sure the audio will be great, because unlike the others there is a real want to make a great game, rather than to get it released on a certain day