Good cars for first time drivers?

I'm looking to buy a car for my son who will be driving for the first time once he passes his tests roughly in December.

What would be the best car for me to buy him taking into consideration first time driver insurance and all of that. I will also be putting myself as a named driver on the car so the insurance is slightly cheaper.

I have seen a few that i like such as an Audi A3 or Mercedes A160 on monthly contract but these may be too much for a first time user and so maybe a ford focus or a kia or something along those lines?