I got to thinking this because I never completed the Battle Frontier of Emerald, and I remember thinking that the Starf Berry is supposedly only available in that generation by full completion of all seven facilities --- it seems the most difficult item to get there. But I don't know for sure whether or not that's true of Gen 3, much less of other generations or individual games among generations.
So, what do you think is the most difficult item or are the most difficult items to obtain? Feel free to be more specific or have multiple answers if it isn't as simple as having one categorical answer. (For instance, saying "[item] is the most difficult item to get in Gen 4 because of [reasons], but in Gen 6 it could be said that [different item] is harder to get because of [different reasons].") This goes for anything that could be called an item, including key items and medals in B2W2 like the Top Medalist medal.
It goes without saying that it does not count if you can use outside devices to generate the item in question effortlessly.
So, what do you think is the most difficult item or are the most difficult items to obtain? Feel free to be more specific or have multiple answers if it isn't as simple as having one categorical answer. (For instance, saying "[item] is the most difficult item to get in Gen 4 because of [reasons], but in Gen 6 it could be said that [different item] is harder to get because of [different reasons].") This goes for anything that could be called an item, including key items and medals in B2W2 like the Top Medalist medal.
It goes without saying that it does not count if you can use outside devices to generate the item in question effortlessly.






