Buffel Salt's romhacks of XY and USUM are pretty fun in their own ways. They're called Eternal X / Wilting Y and Photonic Sun / Prismatic Moon.
They have a bit of a Drayano vibe in terms of changes [harder trainer fights, buffs to weaker mons, everything's available, etc.] and I've enjoyed them both so far, though I will say they are a PAIN to nuzlocke due to how they reworked the exp gain to revolve around the exp share.
Some other hacks.. Gaia is really fun, and has some nicely updated features despite being a gen 3 romhack. Adventures Red is also a good time, it follows the manga storyline. Dray's other hacks of Blaze Black/Volt White or Sacred Gold/Storm Silver are good times [though BBVW is fucking wild with all the multi-battles in it]. Prism is a classic.
