Of All Time is a popular running gag in the series and is frequently used by Washington, after being troubled by his companions' and/or events.
Worst Throw Ever. Of All Time
In Reconstruction: Chapter 6, Caboose throws a spike grenade into a wall directly in front of him and Wash during a fight against the Meta. This is the first time Washington says "Worst Throw Ever... of All Time". After which, Caboose responds by saying, "Not my fault. Someone put a wall in my way."
Second Worst Throw Ever. Of All Time
In Reunion, Tex causes an avalanche by detonating charges. Washington was stuck on a falling piece of land, so Doc attempts to help Wash by throwing the tow hook on the Warthog to him. Since Doc's throw didn't go very far, Washington refered to it as the "Second Worst Throw Ever... of All Time".
This is the Worst Gun Ever. Of All-
In The Sarcophagus, Wash and Carolina fight against a flamethrower soldier and Wash attempts to use a Fuel Rod Cannon on him. However, the shot bounces past the soldier and blasts safely behind him. Wash then comments on why someone would make a gun that bounces, and referred to it as the "Worst Gun ever... of All-", unable to finish because Carolina body tackled him away from the flamethrower flames.
The Biggest Season Ever. Of All Time.
The Season 10 Preview Trailer announced that Season 10 is "The Biggest Season Ever. Of All Time."
Worst Wingman Ever. Of All Time
In Fall From Heaven, Tucker asks Epsilon if he knows any woman who aren't bitches that won't sleep with him. When Epsilon says that's all he has in life, in which Tucker replies: "You're like the worst wingman ever", to which Caboose adds "Of all time."
That Sounds Like the Most Delicious Punishment Ever. Of All Time.
In Don't Say It, Sarge threatens to turn Grif's face into hamburger meat for not "coming on the double." To that Grif states: "That sounds like the most delicious punishment ever." To which Simmons replies with, "Of all time."
- There is a shirt on the Rooster Teeth website, which has another version of the joke. The shirt says "Worst Shirt Ever... Of All Time" and also has a conveniently placed spike grenade on the back of it.