Whichever tiles you like. There is no best it's all preference. I personally prefer the tiles with a bit of texture to them so there is some grip, unlike the smooth gloss coated ceramic tiles.
Mirage came out of brumation on April 26. He was doing great. On May 2 he started acting funny. We just redid his tank, and he keeps going into one of his hides. He just lays there. He shows no intrest in food. HELP!