When I travel, I tend to keep my bags as light as possible. Doing so tends to make my trip more enjoyable as I'm not lugging around a massive suitcase with me everywhere I go and, when I return home, I don't need to worry about trying to fit tons of new junk I bought on my trip into our very limited amount of space as my carry on bag wouldn't have the room to keep trinkets in, in the first place. But not everyone thinks like me. A lot of folks prefer traveling with heavy, tightly packed suitcases so that they don't have to go with out all of their favorite things while they're on the road. On the way back, they'll have tons of space for mementos, too. But they have to be careful--if their suitcases wind up being heavier than their airline allows for, getting the bags on board a plane can get expensive, fast. In instances like this, it's good to have a reliable luggage scale with you, to ensure you know how much weight your schlepping around.
I recently tested a number of these scales for Reviewed.com, in an effort to find the best one. The data I collected showed that, objectively, there's no much difference between one scale and another. If they're weighing bags that are under 50 pounds, you'll get pretty similar results. Higher than this, and the weight will force the scale owner's arm to shake, as it's being strained, causing an inaccurate reading.
My pick for the best scale of 2018, costs around ten bucks. You can read all about it, here.