My first nightstand was a plastic storage cube from a big box store, the kind with a fabric bin that slides into it like a drawer. It held a lamp and a glass of water just fine until the day I knocked the glass over at 2am and watched the water sit on top of the particleboard lid for exactly as long as it took to swell the corner into a permanent little wave. Lesson learned: a nightstand gets treated worse than almost anything else in the house, because you use it half asleep, in the dark, and it has to survive that.
The difference between a good one and a bad one shows up in the same three places every time. Look at the joints first, pull a drawer out if you can and check whether it's actually joined at the corners, dovetailed or at least doweled, versus just stapled and glued, which is what gives way within a year or two of real use. Then check the top surface, because that's the part taking the brunt of water rings, phone charging cables, the occasional candle left burning too close to the edge. Solid wood or a proper veneer over real wood will take a coaster mishap and clean up fine, while the laminated stuff just stains and peels at the seam. And weight tells you almost everything without even opening a drawer, a well made nightstand has some heft to it, a cheap one feels like it would skid across the floor if you leaned on it, which, for the record, it will. On sizing, the rule I keep coming back to is that the top of the nightstand should sit roughly level with your mattress top, maybe an inch or two above, because reaching down for your glasses or your phone at 3am is its own small daily annoyance you don't need. Depth matters more than people account for, too, a nightstand that's deeper than your bed frame's side rail is going to stick out into the room and catch a hip every time you walk past in the dark. If you're furnishing a bedroom from nothing, start with one solid wood nightstand with at least one real drawer, a shelf below is nice but not essential, and resist the urge to match it exactly to the dresser, a close cousin in tone looks more intentional than a perfect set anyway.
Before I buy one now I ask myself whether I'd trust it with a full glass of water at midnight and not think about it again until morning.