If "sober" refers to being not drunk:
* Intoxicated
* Inebriated
* Drunk
* Tipsy
* Sloshed
* Under the influence
If "sober" refers to being serious and responsible:
* Frivolous
* Careless
* Irresponsible
* Reckless
* Unrestrained
* Flippant
If "sober" refers to being calm and composed:
* Excited
* Agitated
* Nervous
* Flustered
* Emotional
* Unhinged
Please provide more context about how you are using the word "sober" so I can give you the most accurate antonym.