While RVs occupy the other entries in this slideshow, the Eriba Touring 820 trailer is brilliant enough to earn a spot, too. At 8.5 metres, it's bigger than some of the motorhomes on this list, and that's not even considering the vehicle you'd need to tow this huge rig. There's also 2 metres of headroom inside, so only especially tall occupants need to worry about hunching over inside.