@mammasaurusrex There is no best, they all have pros and cons:
The Switch has a variety of systems to choose from at a variety of prices as well as a great library. It has affordability, portability, and a kid friendly library with lots of variety going for it. Minus points include the quality of the controllers, which is poor and prone to drift.
Xbox has Game Pass which is great value as well as the Series S which is a very affordable console.
PlayStation has exclusives, which might matter less when kids are concerned but it is going to be a great system for the whole family to enjoy.