D/P/Pt:
- The physical/special split was one of the most important changes to Pokemon battles, and I almost find it hard to go back to any older games that don't feature attacks in the same way
- Sinnoh is one of the most beautiful regions to explore, with lots of different settings (snow, swampland, forests, water routes, canyons, etc.) that made the region feel a lot bigger than it really was
- The fourth gen brought a bunch of new evolutions/pre-evolutions to older Pokemon, making certain lines finally feel complete instead of like they were missing a step somewhere
- Taking the franchise online was a huge step forward, letting us trade, battle, and play with people from all over the world
- You can carry an infinite amount of items in your bag, which was a welcome change, since even gen 3 limited the amount of items you could hold, which meant you had to pick and choose what you actually needed, and what you were saving for a rainy day