IMO, a Class B or Class C are the easiest.
Biggest advantages: can go from the drivers seat to the potty (or kitchen for a snack) without going outdoors.  Can arrive at your destination in a downpour, push a button to start the genny - and you are camping.
Advantage of the B over the C: can park just about anywhere - no toad needed
Advantage of the C over the B: WAAY more cargo and living space.
We've had both a Class C and a van conversion - for the most part, all we ever hooked up was shore power, so leaving for an errand was no big deal (and without a toad, you learn to plan your stops before you arrive at a campground)