i haven't played pokemon in a long ****ing time. the last games i owned were gold & silver, in addition to having red, blue, yellow, and pinball. the only i still play is pinball, mainly due to the fact that i can't find any of the others (and it's fun as ****), but since completing gold and silver i haven't bothered in playing any other games.
so.
what're the main differences between rbysg and all the ones that came after them? and should i invest in getting any of them?
Id suggest getting Emerald. it is really fun i also liked leaf green and fire red. if you liked red/ blue/ yellow get leaf green or fire red if you liked silver/ gold get emerald. if you have a DS i suggest you import diamond or pearl. look up these games! i recomend NOT getting Ruby or Saphire because now you can get Emerald!
The differences between them are that 1. games after Crystal are not compatible with the older ones, 2. all major Pokemon games after Crystal have been on the GBA, and 3. the GBA games can have 4 player matches. If you're serious about collecting every single pokemon, you would probably have to get Sapphire, Ruby, Leaf Green and Fire Red versions. If you're just wanting to get back into the series, don't buy them and wait for Diamond and Pearl to come out for the DS.