1. 1" or 2" Hexagon Tile: I'm not kidding when I say I've used this tile in about 95% of our homes. Many times on bathroom and shower floors because it just works. Pair it with a contrasting grout for bold pattern or match the grout to the tile for a more subtle look. This tile works in any style home but I love it most in a traditional setting and also one that steers towards mid century modern.
2. 3" x 6" Subway Tile: You knew it would be on here. There are so many variations of this and of course the most classic route would be a gloss or matte white subway tile, but it will always be a great size for walls in kitchens, bathrooms, fireplace surrounds, basically anywhere wall tile goes. There are a million ways to branch out on this classic - grout choice, layout, textured, handmade edges, different colors, mini, elongated - but if you're wanting to make a lasting choice choose a white gloss or matte.
3. Penny Tile: Even after a century of being a popular pick for homes, this tile is still so fun. It comes in so many colors and finishes, but I love a white, gray or black penny with contrasting grout. I also love the juxtaposition of this cute shape done in a high end material like marble. It's excellent for areas that need some slip resistance because you get a bit more of a grout area with the tile being round. This tile with a 3"x 6" subway tile provides a great difference in scale and shape ultimately creating a timeless space that doesn't take itself too seriously.
4. Basketweave: Done typically in a white porcelain with black "dot," this pattern also looks great in a marble. This is probably the most formal pick of all the tile and is usually done in high end traditional homes, but I think this pattern also pairs well with subway tile and hexagon tile in any type of home.