What is the best fusion tokamak?

Could you please elaborate on what you mean by the "best fusion tokamak"? Is there a specific metric or criteria you're considering, such as efficiency, stability, cost, or the ability to produce net energy gain? Additionally, fusion tokamaks are constantly evolving and improving, so the "best" one could change over time as new technologies and advancements are made. It would be helpful if you could provide more context or specific requirements to better understand your question.