If you are searching for a cabinet of a specific width or depth, it’s because you already know where it will be placed and how much room can be dedicated to it. Another thing you should look into though, is whether there will be enough room for the doors of the cabinet to open fully, without banging into a wall or another piece of furniture. Also consider the height of the unit, and whether it is likely to look too imposing in the space it will occupy.
Here are two examples – a bit dull-looking if you ask me, but I’m sure they do the job:
24-inch-wide storage cabinet pictured: ClosetMaid 24-Inch Wide Laminate Pantry Cabinet, in alder and white