The thing is, when you're choosing a game, the only way you can know how much fun it will be is if you rent it (I'm not going to go around renting EVERY game before I buy it) first, or if you believe other people's opinions, who might say "This game ROCKS!" while you end up hating it.
Another thing is that the quality of the graphics can usually be rated by a couple groups as fantastic, and almost everyone else will agree, because graphics aren't like gameplay in any way. They're a set thing, and there will pretty much always be a huge majority of people all saying the same things about the graphics in a game. The same cannot be said for gameplay, in which everyone has different tastes.
I like to make decisions based on graphics, gameplay, and even sound sometimes (I cannot stand horribly annoying sounds/voiceover in a game). The graphics can affect the gameplay in some cases, and the gameplay might change your outlook on the graphics (hard to explain, this is long enough already).
So I'm just not going to vote. I see both of these options as being tied into how much fun you have when playing a game, and when you vote you have to think about which of those is tied into how much fun you really have while playing the game the most.