Easiest is a Class B motorhome followed by a Class C motorhome. With either a Class A motorhome or a 5th wheel trailer you will be towing something. With the 5th wheel it is the trailer which you can leave at a campsite and travel around the area with your truck. With the Class A MH you will need to tow a small car so you can leave the long MH at a campsite and use the smaller vehicle to get around the area.
Only with a Class B MH can you travel much as you would with a large SUV and pull over anywhere or park anywhere and fit into any campsite in an area. The longer the overall rig the more restrictive it is in this regard.