Choosing a teether is an individual matter and depends on your child's needs and taste. It's best to let the child make choice on his own.
Therefore he should have a couple of teethers at his disposal. Not just to choose a favourite, but also because babies get easily bored and need changes. However, it's worth knowing that there are different teethers to satisfy different needs of the teething baby.
When his gums are very swollen and aching, i.e. just before the tooth comes out, the best teether is a cooling teether, filled with water or gel.
It can be cooled in a fridge and given to the baby to ease the pain.
On the other hand, when the gums start to itch and the child needs something to bite, the best solution is to buy an elastic teether which is made from soft and elastic, but at the same time durable material.
When choosing the teether also make sure that it's light and handy so that your baby can hold it easily in his little hands.
There are also rattle teethers which combine the functions of teether and toy - whereas the elements meant for biting and for rattling are made from different materials.
There are rattles combined with water, gel and elastic teethers, which makes it easy to choose one according to your child's needs.