A conversation masterpiece, and not just because it is a "conversation only" thing, Best of Three does everything important right: It sets and keeps the atmosphere, provides a superbly characterized and likable protagonist and a life-like NPC as a past romantic interest who is (perhaps intentionally as a clever decision) less likable.
The gameplay is straightforward: You can choose what to say from a menu, change the topics to steer the conversation or just think about things. Occasional physical actions are well infused with significance. (My high expectations were let down only in one case when I wanted to convey a sense of closing the conversation by pocketing the returned pen from the table but the response was the default "Taken.")
Best of Three is not just a conversation, it works as a story. It reveals the background in a way that is not forced, and it serves as a prime example of unobtrusively pacing the conversation and guiding it through the stages the author intended to achieve a meaningful progression and storytelling.
Although I did notice a glitch or two (a topic clarification "the his father") the implementation is very polished to the point where I was confidently typing in "sip cappuccino" just because it felt right. Time advances while you look around or think which limits the leisure feeling and makes the encounter real. I found myself weighing carefully on what to focus my attention next. (Changing topics does not advance time which is good, while trying to think about an irrelevant thing does: this might be converted to an out of world action too.)
Best of Three is a pleasant way to spend an hour or two in a Northwest café (or rather, a "coffee shop") going through your high school relationships.