Flooring Tile - What type of tile?!

Im tiling over old tile in the master bath shower area. What type of tile can I use? Stone? Ceramic or porcelin? Im going to be using 12x12 tiles....thanks

If you mean the floor around the shower area, just find one that you like. As long as the old tile and grout are cleaned of any old dirt, hairspray, soap residue, etc and there are no cracked or loose tiles or grout lines use a modified thinset. If you mean shower pan when you say shower area, then 12" tiles would be too large to get them to follow the slope, you would need to extend the drain and your pan will not be up to current code for construction of a pan. If you mean shower walls, unless it's a mud wall, I'd replace the substrate and wuld not go over tiled walls in a shower built using MR board.