Generation 1 pros: Great prequel to Pokémon G/S/C, with the most Pokémon introduced in a generation as of yet. Cons: Hobbled by the Game Boy's memory, meaning the land is quite small. Later medded up with Fire Red, Leaf Green, and better still, the GS remakes.
Generation 2 pros: Extension of the Team Rocket plot, new area called Johto, great sequel to R/B/Y, and an awesome arrangement of League themes for the champion and Red. Cons: Again, Game Boy memory issues mean that either region isn't the size of one. Later fixed in HG/SS, even brought up to speed to DPt's track count, with the GB Sounds item, a key item that allows you to listen to 8-bit music.
3rd generation pros: A tropical new region with some new styles of music. The new teams suit this region well. Brendan is actually cool with his bag-hat and dark hair. Record mixing is what made the replay value. Very innovative, that was. Rustboro/Mauville/Mossdeep City's music gives Kanto's Viridian/other City's music a more tropical feel, I reckon. Cons: The Pokémon look different. Junichi said he has only few favourites. The graphics looked unpolished due to the 2D overworld sprites, which were purposely different to FR/LG's overworld design. The battle graphics were less in R/S/E as well. Just look at Charizard and Venusaur. They look better in FR/LG. Let's have an improved version, thanks.
4th generation pros: A huge, detailed adventure. Puts in everything that was missing or beta in R/B/Y, including day/night, 3D graphics, emphasis on Pokélegends, an actual plot, Pokétch application device, organized bag, defined Pokémon design and sometimes humorous dialogue. It is the vast features that make this generation. The story is rounded out as well. Most of the characters nod back to the 1st generation. Cons: Sequel isn't out yet.
Generation 2 pros: Extension of the Team Rocket plot, new area called Johto, great sequel to R/B/Y, and an awesome arrangement of League themes for the champion and Red. Cons: Again, Game Boy memory issues mean that either region isn't the size of one. Later fixed in HG/SS, even brought up to speed to DPt's track count, with the GB Sounds item, a key item that allows you to listen to 8-bit music.
3rd generation pros: A tropical new region with some new styles of music. The new teams suit this region well. Brendan is actually cool with his bag-hat and dark hair. Record mixing is what made the replay value. Very innovative, that was. Rustboro/Mauville/Mossdeep City's music gives Kanto's Viridian/other City's music a more tropical feel, I reckon. Cons: The Pokémon look different. Junichi said he has only few favourites. The graphics looked unpolished due to the 2D overworld sprites, which were purposely different to FR/LG's overworld design. The battle graphics were less in R/S/E as well. Just look at Charizard and Venusaur. They look better in FR/LG. Let's have an improved version, thanks.
4th generation pros: A huge, detailed adventure. Puts in everything that was missing or beta in R/B/Y, including day/night, 3D graphics, emphasis on Pokélegends, an actual plot, Pokétch application device, organized bag, defined Pokémon design and sometimes humorous dialogue. It is the vast features that make this generation. The story is rounded out as well. Most of the characters nod back to the 1st generation. Cons: Sequel isn't out yet.