Reinforcement learning is the study of decision making over time with consequences. The field has developed systems to make decisions in complex environments based on external, and possibly delayed, feedback. "Microsoft Research, works on developing the theory, algorithms and systems for technology that learns from its own successes (and failures), explores the world "just enough" to learn, and can infer which decisions have led to those outcomes. Our primary goal is reinforcement learning in the real world: understanding how to build systems that work, even when simulation is unavailable and samples are scarce." To celebrate hosting the Reinforcement Learning Israel Meetup organized by the talented Shani Gamrian at the Microsoft Reactor here is a list of three Reinforcement Learning Environments every ML enthusiast should know.