There's a particular kind of evening, late winter mostly, when the light goes early and you end up with a lamp on at four in the afternoon, that a black metal table stops being furniture and starts being the thing the whole room leans on. It holds a drink, a stack of books, a candle burning down to nothing, and it does it without asking for attention, which is exactly the point.
The difference between a good one and a bad one shows up fast, usually within the first six months. A well made black metal table has a powder coated finish that doesn't chip when you drag it across a hardwood floor to vacuum under it, and the welds at the joints are smooth, not lumpy, so you're not running your hand along a seam and feeling where two pieces of tubing got introduced to each other for the first time. Cheap ones use thin gauge metal that dents if you set down anything heavier than a mug, and the finish is often paint rather than a proper coating, so it scratches down to bare metal the first time a ring or a belt buckle catches it. I've owned both. The cheap one lived about fourteen months before the legs started wobbling like it had had a bit too much to drink. The good one has been through two moves, a spilled glass of red wine that wiped off without a trace, and a toddler using it as a step stool, and it still looks the way it did the day it arrived.
These tables suit almost any room that needs a surface that won't compete with everything else going on around it, which is most rooms. They work in a small apartment where you need something light enough to move but sturdy enough to trust, and they work in a bigger house where you've got a sofa that's already doing a lot of visual work and you don't need the side table joining in. They're especially good in a room with a lot of wood, warm rugs, soft fabric, because the black metal gives you one hard, cool note against all that softness, and the contrast is what makes the room feel finished rather than flat. Against a plain wall they sit well with a single plant, a stack of two or three books, a lamp with a fabric shade rather than anything too shiny or modern.
If you're starting with none, go for a simple round or square top on a basic X base or four straight legs, nothing with extra shelving or a glass insert to worry about. Get the shape right first.
I'd put a worn leather chair next to mine, and a lamp with some warmth to it.