Which potion/ether/elixir is the best?

[Zaft]

In my humble opinion normal HP potions/MP ethers/HP-MP elixirs is completely wast of space for high level (when You have over 4k MP for example), very few hundred MP with this recast times is useless. Better use this recasts to buffing Your stats with potentials or inflict status effects with status potions.

While Poison Pots are very useful indeed, Ethers are also extremely helpful when attempting to push content that strains your mana pool. Similar to Shroud of Saints, you don't want to wait for the "oh shit" moment before you use it. Instead, pop an x-ether at 80% MP. Soon as the cooldown is back up, pop it again. And again.