Qantas will fly between Perth and London nonstop in 2018, which will likely be number three on this list, depending on when several other long haul routes (ahem) take off. This is a CG representation of what the coach section will look like.
Delta charges around $1,137 for a round-trip from Joburg to Atlanta and back. If 17 hours seems like a lot, I flew from Cape Town to LA, with this flight in the middle. That was nearly 24 hours in the air.