I never thought about an ideal world that I want to create. The last time I saw a person that want to create an ideal world was very terrible. Uchiha Madara with his Mugen Tsukuyomi and Light Yagami a.k.a Kira with his Death Note. They are not a bad person due to their aims. They just want to make an ideal world, of course with their version. Every person has a different definition of an ideal world. The perspective, the aims, the background, and many other elements. 

For me, the ideal world is where every people can understand each other. Not only human to human but also the whole living things. The ideal worlds will provide mutualism symbiosis rather than parasitism symbiosis. But, I believe this thought has many future shortcomings and problems. As a human, we have limited thought to create an ideal world. We can't just the positive things in life because they will affect the other things in life. 

So, I actually confused to answer the question. I have no capability to answer that question. Simply that something I think an ideal, it always has the other side which is not ideal. I don't want to be Uchiha Madara or Kira.