I am curious. What is in your opinion the best and worst features of each Generation (or a feature you missed from an older game). This is NOT counting the Pokèmon, as each game adds more and more of those anyway...
Generation I (Red, Green, Blue, Yellow)
- Wild Pokèmon...well this game pretty much began it all so the whole game is a new feature
- The HM Flash. Its only required once and in this game you couldn't delete HM-moves. Leaving you stuck with a move that's close to useless in any other situation.
Generation II (Gold, Silver, Crystal).
- Move Deleter: So I can finally get rid of Flash:B
- Introduction of time and Day/night. It was kind of neat.
- Shiny Pokèmon. So long as you don't hack them and make their rarity pointless... Shinies of this generation were also stronger than their normal colored counterpart as they had above average IVs.
- Held items, particularly held berries that allowed the Pokèmon to regenerate health and cure status problems by itself.
- Having rematches with trainers you've fought before, when I run out of people to pwn.
- Too many water Hms. In the first games I would just teach one HM-move to four members of my party and use an HM-slave for Flash (or just walk through the cave without it, it wasn't so hard), if I did that in Generation II I would end up with a water-type with three HM-moves..
- No Joey, I don't care about your Rattata. STOP CALLING ME... Yeah the phone was great but some of these calls got really annoying.
Generation III (Ruby, Sapphire, Emerald FireRed and LeafGreen.)
- Double battles. I would sometimes walk around deliberately looking for one
- VS Seeker. Rematches without the annoying phone-calls.
- No backwards compatibility. If it did I might still have had my shiny Raticate:(
- The berry system started to get really annoying... Planting berries may have been a neat idea, it just takes so darn long and becomes really tedious.
- The time system is more or less useless and has little impact on the game. Day/Night is gone.
- TOO MANY HMS!
All in all Generation 3 was a huge letdown for me and let to me becoming horribly bored of Pokèmon until the release of Platinum.
Generation IV (Diamond, Pearl, Platinum, SoulSilver and HeartGold)
- Return of the day/night system.
- Online Trading. Since I live in the middle of nowhere and none of my friends care about Pokèmon anymore this was the greatest feature ever.
- Walking with Pokèmon. This was technically introduced in Yellow but since it was only your one starter Pikachu I don't really count it.
- Backward compatible with Generation III.
- I STILL DON'T CARE ABOUT YOUR RATTATA... well it was a remake of Generation II after all.
Generation V (Black and White)
- Pokèmon don't stand still in battle anymore (New for the portable games at least).
- Not really a feature but...since learning that there were no old Pokèmon in Unova I was expecting them to be replaced by new ones and I would just meet Woobats in every cave I entered. So far however every cave has had different Pokèmon in it. If only Zubat had not shown up in every single cave in Gen I-IV it wouldn't be half as annoying.
- Many good features from HGSS were missing. Such as the way the game could be controlled without pressing the buttons at all and the auto-run button, and of course Pokèmon outside their Pokèballs (maybe it would have made Team Plasma complain a bit less One less Pokèmon to be trapped inside a ball.)
I don't count the console games here since I've only ever owned one of them: Pokèmon Colloseum.