Final answer:
The correct form of the verb to fill in the blank is 'conozco', which is the first-person singular present tense of the verb 'conocer'.
Step-by-step explanation:
The correct form of the verb to fill in the blank is conozco, which is the first-person singular present tense of the verb conocer. So the sentence should be:
Yo conozco un buen restaurante mexicano.
Learn more about Spanish verb conjugation