LEGO has many fun pieces and one of the most useful and underrated pieces is the one-by-one brick. The brick may not look too exciting but it can be really useful. Not when you are making a building, the one-by-one brick is often needed to fill in gaps that are otherwise hard to fill in. Lego has made one by one with a stud on the side so you can build sideways. The one-by-one has been around since 1954 in the garage and small house set. Overall, I think that people really need to respect the one by one more. If you want to buy a 1×1 brick, go to Bricklink.