Whether you are choosing a new case or planning to replace an old one, a new PC case can help in many ways. PC cases can improve cooling, provide ample space to fit in components, and let you move parts around inside the chassis. More importantly, they can improve the shelf life of your CPU if chosen right.
There are three broad categories PC cases fall into.

Budget Cases
If you want to move your components to a new case and get the barest possible features without a thought on aesthetics or protection, get a budget case. These offer a basic level of protection and let you run your PC components just as they are.

Mid-Range Cases
This offer features such as soundproofing, cable channels for routing wires, extra port connection spaces and much more.
Knowing the case dimensions is an important factor before you get one of these. Before you buy, check what components you have and their dimensions. This ranges from multiple cables, liquid cooling tubes, video cards and huge CPU coolers.
Cross check whether all your components fit in comfortably and that the component’s internal layout in place. You wouldn’t want a long video card not fitting into the chassis due to problems with the internal layout which is why you need to check the dimensions.
Typically, these support 3.5 inch and 5.25-inch devices. Avoid buying a three-bay case if your system uses a four-drive RAID array.
Now comes the creative part – the design. You can choose the colors, textures and overall design of the case. Some cases offer a lighting system too which is fun but offers no functionality. Make sure the design doesn’t interfere with the function of the components. Strike an elegant balance between design and functionality.

High-End Cases
If you’ve got a cash to spare for a chic and futuristic case, welcome to the world of high-end cases. This is where design and functionality max out. Prices can go beyond $200, and cases can come with a ton of advanced cooling features. They also have high-end equipment, fan controllers, and other switchable features. The soundproof acoustic foam covers the internal surfaces. You can get water-cooling loops inbuilt in the chassis.
Cases can come with multiple hard drives and PCIs, ranging from 10 or more numbers in each category. Pricing can get bigger depending on the size and scale of the chassis.
Whatever floats your boat, see if the case you’re going for meets your PC requirements. You don’t want to end up overspending for components you don’t need. On the other hand, you don’t want to underspend either and end up with something that doesn’t meet your requirements.