Gen 1 has the best designs and most SOUL but is total garbage.
>Made by like 4 rushed underpaid guys
>bugs out the ass, can easily glitch out the game and get mew or find missingno and shit
>some moves like wrap are downright broken
>ai is broken and dragonite with barrier will just use it forever against a poison type because it's considered super effect to the archaic ai
>elite four pokemon know shit like tackle and growl
>sprites are horrible until red and blue (the remake of red and green) but they were still too lazy to fix the backsprites
>a third fucking cash-in remake yellow comes along and fixes literally nothing, same game breaking bugs, same shit backsprites, same problems, shitchu follows you now though and you get all overpowered starters for free making this easy game even easier
Emerald > FRLG > Crystal > STADIUM > Platinum > BW2 > SHIT > Everything else
Handheld gen 1 is by far the worst gameplay wise.