A marginal improvement over Pokemon Red and Blue, you have more elements from the anime here, such as being able to have all three starters, Jessie and James from Team Rocket, and a Pikachu that follows you.

The beginning of the game is a lot more difficult because of Pikachu (unless you catch a Mankey to help you), but the wider variety of Pokemon makes this the version you'll want to pick when choosing a Gen 1 game.