Choosing your computer casing

I believe everyone knows what a computer case is,but ill explain in detail what it is and what you need to consider before getting one.
A computer case (also known as a computer chassis, cabinet, tower, box, enclosure, housing or simply case) is the enclosure that contains the main components of a computer.
Cases are usually constructed from steel (often SECC - Steel, Electrogalvanized, Cold-rolled, Coil), aluminium, or plastic, although other materials such as wood, plexiglas, and Lego have also been used in case designs.

Things to know before buying a computer case
Size
layout
appearance

Size
Cases can come in many different sizes (known as form factors). The size and shape of a computer case is usually determined by the form factor of the motherboard, since it is the largest component of most computers. Consequently, personal computer form factors typically specify only the internal dimensions and layout of the case. Form factors for rack-mounted and blade servers may include precise external dimensions as well, since these cases must themselves fit in specific enclosures.
For example, a case designed for an ATX motherboard and power supply may take on several external forms, such as a vertical tower (designed to sit on the floor, height > width) or a flat desktop (height < width) or pizza box (height <= 2 inches) (designed to sit on the desk under the computer's monitor). Full-size tower cases are typically larger in volume than desktop cases, with more room for drive bays and expansion slots. Desktop cases—and mini-tower cases designed for the reduced microATX form factor—are popular in business environments where space is at a premium.Currently, the most popular form factor for desktop computers is ATX, although microATX and small form factors have also become very popular for a variety of uses.

Layout
Computer cases usually include sheet metal enclosures for a power supply unit and drive bays, as well as a rear panel that can accommodate peripheral connectors protruding from the motherboard and expansion slots. Most cases also have a power button or switch, a reset button, and LEDs to indicate power status as wll as hard drive and network activity. Some cases include built-in I/O ports (such as USB and headphone ports on the front of the case. Such a case will also include the wires needed to connect these ports, switches and indicators to the motherboard.

appearance
Through the 1990s, most computer cases had simple rectangular shapes, and were often painted beige. Beige box designs are still found on a large number of budget computers assembled from generic components.
Case modding is the artistic styling of computer cases, often to draw attention to the use of advanced or unusual components. Since the early 2000s, some cases have included clear side panels or acrylic windows so that users can look inside while it is operating. Modded cases may also include internal lighting, custom paint, or liquid cooling systems. Some hobbyists build custom cases from raw materials like aluminum, steel, acrylic, or wood.

The case type you want to get deppends of your needs and your style. I say that any case that can have my motherboard and my hardware is good enough, so you dont really need a super awesome case, but just any good and cheap computer case will do.