This paper examines English language learners' preference for student-teacher and student-student debates based on a study of second-year students at a Japanese university. The paper first discusses the amorphous nature of academic "debate", then presents a literature review addressing the benefits and drawbacks of debate in the language-learning classroom. In the ensuing study, 45 students first debated their instructor one-on-one and then debated a classmate in the same fashion. Afterwards, they completed a survey indicating which of the two modes they preferred, along with the strengths and weaknesses of each mode. Results showed that while students were generally satisfied with both formats, they preferred to debate the instructor since the discourse proceeded naturally and the dynamic closely resembled the target language environment. The findings may be of particular use to EFL teachers whose students intend to study abroad in an immersive all-English environment.