My favourite :
1. The Southern Seas (If I'm lazy to move and let my pet do the job)
2. Yudra Forest (Chance for double loot from 2 bosses)

If you won't spend any elixir, you have to use fob pendant, lucky pet with timur hb and hisha aa. Hisha aa only an extra, without it your reroll chance already 50%. Don't sell lock at this moment, but wait till certin event came.