3-year old kids can virtually fall asleep on any surface. However, this should not mean that you will just let them sleep just about anywhere. Their comfort is still of utmost importance if you do not want them to wake up feeling cranky. The expression "waking up on the wrong side of the bed" literally applies to them.
So anyway, what exactly is the best one? There are so many options today including air mattress, innerspring mattress, memory foam mattress and latex mattress. Many parents purchase air mattresses especially those with cartoon character prints.
This is a practical choice as kids tend to outgrow their beds in no time. This is a good option for you but make sure it is also comfortable. Check some reviews and find the ones that have been labelled comfortable by consumers. Make sure the materials are also non-allergenic. PVC materials are often used for inflatable beds but these can trigger allergic reactions.
What is great about inflatable beds is that they are water proof. If you child wets on the bed, you can easily clean it. This is difficult to do with other mattresses.
Innerspring mattresses are not goof for playful kids as they tend to jump on this soft mattress. This will lead to mattress depression which will then lead to back pains. If you want to choose this bed, make sure it has less springs integrated. With more springs, the thinner springs are integrated. Less springs mean thicker springs are used which will give the mattress a desired level of firmness. A firm surface is also ideal for children as they need back support.
Memory foam is ideal for back pain. However, this may not be a good choice for kids as they are loaded with all sorts of chemical. The chemical content of this mattress may trigger allergic reactions.
The last choice, but definitely not the least is latex. This has been coined as the best mattress for kids because of its lack of chemical content. The mattress is naturally hypoallergenic. Also, the density of the mattress is just right for kids. It is not too firm and not too soft so kids can have the most relaxing sleep.
I would have to say latex mattress is a worthy investment. It has a long life so you can use it for your next children or sell it when your child outgrows the mattress. You can also purchase an adult size already and this will be your kid's mattress for many years to come.