Mmmmmmm Coffee! +10 to initiative, +12 to alertness, -5 to "Boss Run In While Taking A Break"

I actually don't like the taste of coffee. But boy, do I need it. I do two sugar and two cream to make it palatable. How do you take your coffee? That's not the question, but I'm just curious. The real question is:

What is your favorite\most useless in game consumable? What bonus does it give?

I was playing FF14 and I was running Brayflox Longstop trying to level. It was difficult as it must have been fully silly billy night or something. Had 2 tanks leave during one run. The first just randomly left after the last loot prior to the boss. The second got upset that we didn't appreciate his tactic of "running around in circles" around the end boss. We wiped several times and finally he left, and I left to just go mining. Much more relaxing. However, we kept wiping mostly because I would run out of mana. But it's OK, ETHERS! Oh wait, most useless consumable ever. 28% max MP restored and it's a random amount I believe. 30 minute cooldown. What?! I was even being super conservative as I'd maximize Freecure by only using Cure 1 until I got the freecure buff. But yeah, we just weren't killing it fast enough. OH WELL. I guess I'll never get Regen before the ....Attack on Titan....(HA! YES!)