Does watching a movie with a friend make you more likely to agree on how good it is?

Yes. Experiencing something with a friend makes the two of you more likely to agree on your impression of it:

Two studies examine differences in participantsâ momentâtoâmoment and retrospective evaluations of an experience depending on whether they are alone or in the presence of another person. Findings support our hypotheses that joint consumption leads to similar patterns or âcoherenceâ in momentâtoâmoment evaluations and that greater coherence leads to more positive retrospective evaluations. We trace the emergence of coherence to processes of mimicry and emotional contagion in experiment 1 by comparing evaluations for pairs of participants who could see each otherâs expression with pairs who could not do so and in experiment 2 by coding participantsâ facial expressions and head movements for direct evidence of contagion.

Source: “Consuming with Others: Social Influences on Moment-to-Moment and Retrospective Evaluations of an Experience” from Journal of Consumer Research.