The type of washer and dryer you get will depend largely on where it’s going to go in your home. For example, laundry might be allocated to a narrow closet in your home, making the 24” units that is stackable your only option. Also, you will need to choose how you want your dryer to operate; vented or non-vented, so which one you purchase will be a result of what your house supports.
If space is really an issue, available is the washer-dryer combo. This unit combines in a single cabinet a washing machine and a clothes dryer. It should not be confused with a "stackable" combination which houses a separate washing machine and a separate dryer. This unit doesn’t require to be vented, however the drying process is longer, and you can only dry half a load at a time.
For those who have a basement setup or dedicated laundry room where there’s room to place them side-by-side, you’ll need to decide on the size and if you prefer a top-load or front-load washer.