What it is
Class C is the compromise most families should look at first. You get two separate sleeping areas, standing headroom at the rear, a real galley, and a chassis that handles better than a Class A.
Why people choose it
Look hard at the over-cab bed. It runs warm in the summer and cold in the winter, it is the first place heat escapes, and on many models it is only approved for children. Adults will not thank you for it after a month.
What to check before you buy
Payload matters more than length. A family of four plus luggage can use up 300–500 kg of payload before you have even filled the water tank. Do the sums with real weights, not with the brochure's unladen weight.