Wear your heirlooms @ lvl 80 to make 80-81 faster.
Grind lvl 81 maybe up to 82 if you can stand it in BRC normal.
Hyjal Quest here till 83
Deepholm Quest till 84 -- Throw in a stonecore run or 2 to switch it up.
Twilight Highlands Quest till 85 -- Love this place. You can always mix in some Lost City, Vortex Pinnacle, HOO, Grim Batol (I did) on the grind to 85.