I'm going to be replaying some of the older games soon, and I'm wondering about some of the better stuff to transfer to later gens apart from unavailable legendaries. I know about these:

>Emerald exclusive move tutors
>HGSS Apricorn Balls(they're back, but only 1 per ball)
>HGSS ExtremeSpeed Dratini
>XY Friend Safari exclusive hidden abilities/balltism for starters and some other Pokémon
>ORAS exclusive hidden abilities
>move tutors(for now, hopefully)

Is there anything else I should be looking out for? I think the Gamecube games had some exclusive stuff as well.