gaming cases tend to be flashier .... but also often more flimsy (and thus noisier)
a good PC case should fit the space you intend it for (ie full midi or desktop etc)
MUST have at least two 8cm or larger fans (never remove ear slot covers and leave them open).
preferably a couple more 5.25 and 3.5 slots than you currently need (for future use).
and should have enough depth so that you can keep all cables out of the main airway
and front outlets for usb & earphones etc