Warhammer 40,000 takes the amp, scrawls twelve and thirteen on the amp in gothic script and then plugs it into a Slaaneshi Noise Marine's Blastmaster, causing heads to explode all over the planet.
And the Orks would cheerfully turn it up to seventeen if any of them could count that high.
Tzeentch would then turn the knob backwards....to 999, then clasp his hands.
Examine a Warhound battle titan sometime◊. One of the largest and most expensive Forge World models in existence, armed with some of the most powerful guns in the game, and guess what it is? A SCOUT TITAN! The battle titans are so big they don't make models for them.
Forgeworld now make Reaver titans. These guys are bigger than Warhounds and mount an extra weapon on their top carapace. There can only be time before these gentleman crank out a Warlord titan...
There are official rules for Warlord Titans and some fans have made them. They are about four feet tall.
Those are not even close to what they had before the Age of Strife hit. During the Dark Age of Technology they had even BIGGER Titans. Why don't they have them now, you may ask. Well, many things were lost in-between the Dark Age and the 41st Millennium.
The standard sidearms go to ridiculous extremes already. Their numbers include laser guns that can blow limbs off people with a single beam, guns that spray razor-sharp shards of crystallized neurotoxins, guns that spray even sharper shards of crystal, guns that fire rocket-propelled armor-piercing grenades, and railguns that vaporize their iron slugs before firing them. And these are the sidearms.
You have to buy 11 or more Orks for all of them to get the Fearless rule.
11 is also the minimum number of barrels on a Baneblade.
Don't forget that the spaceships the Imperium currently uses were freight ships back in the dark age of technology and titans were used as normal transport utilities. Turned Up to Eleven indeed.
The Tau will, in desperate times, unleash an XV9 battlesuit to lead their XV8 battlesuits. Tau count in base 8.
The latest codex has added an XV10 which is twice the size.
The card game Munchkin has a card named "Mine goes up to Eleven!" If you play it, people have to reach level 11 instead of 10 as usual.
Magic: The Gathering has a mechanic called "protection" which made a card essentially immune to a certain source (A card with "protection from red" can not be blocked or damaged by red creatures, or targeted by red spells and abilities). Until recently, the mechanic was limited to phrases like "protection from black" or "protection from red" or "protection from artifacts", or occasionally "protection from creatures". Then along came this card.
Most MTG cards at the new "Mythic Rare" rarity level fall under this trope.
...et cetera. Although not all Mythic Rare cards make use of an existing mechanic, it's not worth making a card Mythic Rare UNLESS its potency is cranked up to eleven.
"Darksteel Colossus" has 11 power, 11 toughness, and costs 11 mana. Oh, and it's indestructible. Not only that, but if it is somehow sent to the graveyard, it's shuffled into its owner's library instead. This ability (which also appears on the aforementioned Progenitus) is actually meant as a drawback, as it prevents players from discarding or milling it and then reanimating it.
Blightsteel Colossus does all that, plus has infect. Infect deals poison damage, which can't be healed in standard and it only takes 10 points to kill you. Yes, Blightsteel Colossus can One-Hit Kill you without even trying.
Zendikar is Everything Trying to Kill You taken up to 11. Get some Rise of the Eldrazi cards and you can take it up to 15 (the linked monster nukes six of your cards simply by looking at you funny, and is almost impossible to kill).
Scion goes up to eleven. See, it has a system known as Legend, and Scions, gods and other supernatural beings have a Legend score, and they're able to take Epic Attributes and Boons equal to their Legend score minus one. The maximum Legend score is 12. Therefore, the maximum you can take your powers to is 11. The 11-dot Boons and Epic Attributes are the Avatars and Ultimate Attributes, at which point you become a force of nature.
The Dresden FilesRPG takes Up To Eleven...Up To Eleven. The section on the Laws of Magic describes breaking the Fifth Law (Never reach beyond the borders of life) as giving an exaggerated arrogance over one's power over life and death, like a doctor's God complex turned Up To Eleven. In the hand-scribbled notes, Harry himself crosses out the eleven and adds "Thirteen", leading himself and Bob to do a brief parody of the Trope Namer ("...These go to THIRTEEN," Harry insists).
Larloch had a level one above what was possible for his class, by Word of God (the intended implication was 'he'll always be more powerful than the player characters, no matter what'). Then the edition changed and rules were published that made it possible to reach that level.
Before the fall of the Netherese Empire, the spell levels literally went up to 11 (compared to the Mystran regiment of 9). Then some overly ambitious wizard decided to make a level 12 and... well, that's why they are limited to 9 since then.
What made Pun-Pun such a Game Breaker? Firstly, the fact that he could grant himself theoretically any ability. Secondly, the mechanic that allowed him to do so provided no limitation on how powerful those abilities could be: if he grants himself the ability to cast a spell, he can let himself cast the spell at a caster level of Graham's Number in a game where the most powerful statted monsters rarely break thirty. He can also grant himself any number of Divine Ranks, even hundreds or thousands, when the Powers That Be max out at 21.