It depends. I teach at a YMCA, and we are in two rooms, one on Monday, one on Thursday. The Monday room is a dance studio with a rubber/plastic tile floor of a type I've never seen anywhere else; the tiles are about a foot square and are raised from the surface they are attached to, which I think is cement - the bottom of the tiles looks almost like a bathtub mat, the type with the suction cups, but closer together. It's an odd surface (and slippery when dusty) but fairly gentle on the feet. The Thursday room is also a dance studio, but converted from a racquetball court, and still has the racquetball court wooden floor.
My sahbum's class is in a gym, which has a rubberized floor which took some getting used to; it's slightly sticky, but with very little give for the type of surface, not quite as good as a wood floor, but not bad at all. When I started, we worked out in a room that had a cement floor, so almost anything else is an improvement.
My basement workout space is puzzle mats over cement, which is nice, but almost too soft in some ways; it's hard to pivot on them, especially as I'm used to harder surfaces everywhere else.