On ds platinum is best and on gba there are quite better hacks available like light platinum and in original pokemon gba games emerald is good. Both improve on their predecessors (diamond & pearl and ruby & sapphire). For emulator you best play gba games as you can get the pokemons that can't be caught by trading from your other save file which can't be done in ds emulators.
Pokemon Mystery Dungeon: Explorers of The Sky. The only game that make me crying at the end of the story.
I recommend you start from 3rd gen, 1 or 2 are out of date in graphics especially if your emulator is in PC, after that try 4th gen and up, try 1 by 1 because you CANNOT collect them all just from 1 ROM ...I mean from 1 game mainly because some Pokemon are exclusive (mascot legendary) and some of them can only be obtained by trade (evolution by trade, evolution while holding item by trade, evolution with specific Pokemon while using trade)
EMERALD!!!! emerald is the one I have played the most. Regardless of that you do wanna play all of them upto b2/w2 as citra is currently in development. Oh and understand stuff about heartgoldsoulsilver before playing them as they get corrupted really fast due to security stuff. Also try mystery dungeon series of pokemon. There are many great games that are almost a must for emulation but start with pokemon first. You can branch out to fan made pokemon games like pokemon prism too.
Platinum for Sinnoh since its the third version. Same for Emerald for Hoenn since its the third version. They tend to have a more 'polished' story than the earlier two versions. HeartGold/SoulSilver is an awesome remake of an already awesome generation in Gold/Silver/Crystal so you should play either. Gen 5 BW and BW2 has an amazing story.
Mystery dungeon if you tired of put living being on small ball And pokemon card game for wasting time with good manners Too bad mamoswine only available in gen4 after elite four
Platinum, it has a cool story and the starters are definitely the best, and also becos... HAIL GIRATINA
The first few mystery dungeon games are great. As for mainline Pokemon Black and White are probably the best in the franchise.
Hmm, I've played Diamond, Platinum, Black, Soul Silver, X, Moon and Explorers of the Sky (of the dungeon series) so far. I can recommend all, but Soul Silver was definitely my favorite (although the graphic in X and Moon is sooo much better) and Diamond will always be the very best in my heart (it was my very first pokemon game ever, there are so many memories connected with it). And for the dungeon series, well, I only really played one, but this one I can definitely recommend, it was very fun to play.
Pokemon Emerald was my favourite Pokemon game. It was probably the most memorable Pokemon game for myself. Platinum and Black 2 were also pretty fun to play as well.
My favorite was Sapphire and HeartGold. Oh and there’s also Conquest. Pokémon X was fun too but i felt it was a bit too easy
Probably heart gold/ soul silver . 16 gyms , Pokemon following you, great story and best looking sprites imo.
Ruby / Sapphire would have to be my favourite Pokemon game, largely due to nostalgia, but also because it hosts some of the best Pokemon designs. I always enjoyed the underwater element of the game, even if it became somewhat tedious on the replay. Also Wally.