When it comes to graphics I tend not to care as much either way. There's definitely something to be said for both 2D and 3D graphics when they are well done, and each can capture things that the other can't.
As for gameplay, however, I find 2D to be far superior to 3D in most cases, with the clear exceptions being games that simply can't be done in 2D. Even then, I tend not to like 3D games even if they are exclusive. The way I see it, the D-pad is 2D and so is the television, so 2D gameplay is naturally easier and more intuitive to construct, understand and control. The fact that there is no 3rd axis also means that there is much less information for the player to process, in spite of the fact that we can better relate to 3D physically ourselves. What that means is that 2D games can have much more action and intensity overall, and often be more precise. These things among others, I feel, are key elements in making good gameplay.
Since I consider gameplay to be of the most critical aspect of a game, you probably won't be surprised to hear that my collection consists almost entirely of 2D games. It's good to see so many others of similar tastes here. :thumbs-up: