Incredible item-farming run that was just pointed out to me. Take the Kill Malathel quest in A5. Go all the way to the last checkpoint that you get right in front of the portal to the Malathel boss fight on fortress level 3. Leave the game, re-enter, and take the town portal to that checkpoint. Go back up to level 2, and you have about a half-dozen chests to open, two rares or treasure goblin, and two purple elites to kill on that sequence of platforms connected by death gates. You can clear all of these in like 2-3 minutes. Celik, one of the purples, also drops angelic shards for Hallowed crafting. Then just leave game again and repeat.