Iconic

Etymology

From Greek eikon, "image," via icon. The strict sense is "resembling or serving as an emblem," but stan and pop-culture communities inflated it in the 2010s into a superlative of praise, so a single funny remark can now be called "iconic."

adjective · /eye-KON-ik/
Memorably excellent, instantly recognizable, and worth celebrating — the stuff of legend.
What it names
In its slang sense it awards a kind of instant canonization: a moment, look, or line so distinctive that it deserves to be remembered and quoted. It elevates the everyday to the level of a cultural landmark, often with playful exaggeration.
Example
She showed up an hour late, unbothered, and gave zero explanation — iconic behavior.
Related idea
Stronger than memorable: something memorable merely sticks in the mind, while iconic implies it has become a reference point others recognize.