Start on quest 6, The Broken Blade, on the sub-quest Talk to Alaric
Run to Warrior's Rest
This one will, most of the time contain(from my findings, about 20 runs), a rare spawn monster and two chests.
Kill the rare, loot the chests, leave game, and click resume.
You'll be back at Warrior's Rest
Rinse and repeat
(I was getting at least 1 rare per run with nearly all MF gear on)
NOTE: If you want, there is a chest there right as you spawn (most of the time), and you don't have to kill the rare for it. So, you can just keep spamming that chest.
EDIT: Just got Bul Kathos, sweet