Final answer:
The word that best completes the sentence is 'ir', which means 'to go' in Spanish.
Step-by-step explanation:
The word that best completes the sentence is ir. The phrase 'Me gusta ir en una discoteca' translates to 'I like to go to a disco.' In this sentence, 'ir' means 'to go' and is the appropriate verb to use in this context.
Learn more about Completing sentences in Spanish