Despite the massive balance issues, the roster is incredible.
Going deeper than "they're the most iconic set," you have three starters that range perfectly from simple and adorable base designs to badass and imposing final stages. You have a good mix of plain, more terrestrial Pokemon that are realistic stand-ins for real life wildlife, and more exotic types that open up to you as the game progresses. Yeah Jynx and Mr Mime are perhaps too weird, but as a whole the designs are quite elegant, establishing character with very simple shapes and motifs. And Mewtwo, an abomination of science, is one of the coolest creature designs ever.
