General:
* Retort: A quick, witty, or cutting reply.
* Repartee: A conversation characterized by quick, witty, and often amusing exchanges.
* Riposte: A quick and clever reply to an attack or criticism.
* Comeback: A clever or witty reply, especially to a criticism or insult.
More negative:
* Snappish: Short and rude, implying impatience or irritation.
* Sarcastic: Expressing scorn or mockery through irony.
* Scurrilous: Abusive, foul-mouthed, or insulting.
* Bitter: Expressing anger, resentment, or animosity.
More positive:
* Witty: Clever and amusing.
* Clever: Intelligent and inventive.
* Sharp: Quick and insightful.
The best word will depend on the context of the conversation and the tone you want to convey.