If you're thinking about the emotional impact:
* Joy: This is a direct opposite of the sorrow and despair associated with tragedy.
* Happiness: Similar to joy, but broader and encompassing a range of positive emotions.
* Triumph: This suggests a successful overcoming of adversity, the opposite of a tragic downfall.
If you're thinking about the narrative structure:
* Comedy: Traditionally, comedy stands in contrast to tragedy in dramatic literature.
* Happy ending: This refers to a resolution that leaves the audience with a sense of satisfaction and optimism.
If you're thinking about the nature of the event:
* Miracle: This implies a positive and unexpected occurrence, defying the tragic nature of a situation.
* Success: A successful outcome stands in contrast to a disastrous or tragic event.
Ultimately, the "opposite" of tragedy depends on the context and the specific meaning you're trying to convey.