What I see more and more now a days is natural stone, straight line, tight grout joint work. The problem with natural stone is it's maintenance. It needs to be kept cleaned and sealed or the pores in the stone will soak up stains. Some stones more than others. The problem with tile, is that depending on what tile you get, because the inconsistencies when the tile is fired and shrinks slightly make it harder to get a grout joint any tighter than 1/8".
Let me share with you what I'm seeing more and more, and personally liking: rectified porcelain tile. What is rectified tile? Well, it's tile that, after it has been fired, is cut into straight and square pieces with slightly beveled edges. Because the cutting process gives it a straight line, as straight as any stone tile, it can be laid with little to almost no grout joint. Gone are the days when you see 1/4" or larger grout joints. No one wants to see grout. I will usually pick a grout that matches the color of the tile as much as possible to further hide the grout line.
These are 1/16" grout lines, and even they seem too big when pointed out. But choosing the right grout color can make or break even the smallest of grout lines.
So why porcelain? Well, lets put it this way, all the look, have the work. Porcelain comes in so many colors, looks and styles now a days that some would even be hard pressed to tell the difference between natural stone or porcelain. And porcelain has the added durability, over ceramic, and nearly no need to seal like natural stone. Notice how the grout lines in these wall tiles virtually disappear and the tile looks like natural travertine.
So for your next kitchen or bathroom remodel take a serious look at porcelain, rectified tile.