There is no real best glove, it all depends on the type of sport you practice and your preferences regarding padding. In fact they are of 5 types: Latex, Foam, EVA, Mixed and Horsehair. The latex padding, after the blow almost instantly returns to its original position, on the other hand it is not very resistant and the knuckles will touch the object or the opponent, which can be dangerous for the health of the hand of the athletes I tend to load all their shots with such force. The EVA, and the mixture, is a much more resistant padding, and in no case will the knuckles come into contact with the struck object, at the same time delivering a knockout blow, for example, will be more difficult. The blend offers a middle ground between these three, resulting in a more expensive padding. In fact, foam also does the same, but with lower performance at a lower cost. As for the horsehair padding, it's a different matter; They are gloves made exclusively for matches and to KO the opponent, and are also not very protective for the hand. Also, with each round, the padding will flatten and compact, making the glove less and less protective. After the meeting they should be thrown away because the stuffing is completely gone.
As for the materials, there is genuine leather and synthetic leather (PU Leather). The former guarantee a softer and more durable glove over time, at a higher price. The second a shorter duration of time, greater rigidity, but at a lower price.
See also: How to choose Boxing gloves, Muay Thai, Kick Boxing, MMA.