First of all, I have max magic find and run on monster power 5.
I start my run in Act 3, and go directly to Keep Depths Level 2. If I find 5 elite packs/champions on that map, I continue my run, otherwise I restart the run.
If there are 5 elite packs/champions, my run continues as follows:
Keep Depths Level 2 ->
Keep Depths Level 3 ->
Fields of Slaughter + Cave ->
Rakki's Crossing ->
Core of the Arreat ->
I have been doing this for a very long time and on mp5 with max MF, I have never not seen a Legendary item drop using this method. Last time I posted this there was much controversy and flaming, so I won't be responding to questions on the thread. If you want, you can contact me in-game for questions.