Marble and Travertine are popular choices with our clients. Marble has a very classic look and comes in a variety of colors but the most common is a combination of white and grey like Carrara Marble. Travertine comes in variations of cream / sand and has variations with brown in it.
Some positive aspects about using natural stones:
Edges can be finished after cutting or rounding off, which allows us to finish edges, niches, accents, etc, without the need of edge pieces IE: Bullnose , Schluter trim or Trim pieces
Edge pieces with different profiles can be found in natural stone : IE bullnose, pencil, ogee, etc, which can help with intricate designs, drawing your eye to certain spaces.
If chipping does occur it can be repaired without having to cut the tile out as the color of the tile is the same throughout as opposed to ceramic and porcelain tile which only have a top layer of color.
Stone can be maintained to bring it back to life either by re-honing or re-polishing.
Some negative aspects about using natural stones:
Weight - Natural tiles are often heavier
Maintenance - Depending on the finish IE : honed, polished, tumbled, etc - tile will require sealing
Looking back at most of our projects it seems that we do around 75% natural stone in bathrooms. Hope some of this helps.