Super Mario World: Just Keef edition: Adds a proper playable Luigi with control differences, and overhauls the game to actually utilize the Dinosaur Island themeing with tons of new enemies and setpieces, all of which for the most part are organically baked into the game rather than just slapping a ton of random glup shittos into the stages for the sake of variety
Final Fight 3 Optimized: Does some wizardry with enemy and tile spawning so that more enemies can be on screen at a time and also negates most of the slowdown the game suffered from.
Super Junkoid: Complete overhaul of Super Metroid with new sprites and everything, and is really well designed! exploration is fun and it has that atmosphere the original game had in spades.
Mario's Mystery Meat: Just. play it for yourself. No description I could give it would do it proper justice.
Mega Man 7 EP edition: Remixed version of Mega Man 7 with tons of new gimmicks, setpieces, and game mechanics! incredibly high effort for a snes romhack.
Rockman and Forte Player switching and multiple equipment: Allows you to switch between Megaman and Bass on the fly and stack upgrades from Otto's shop rather than only using one at a time. It works shockingly well and honestly negates the vanilla release IMO, much as I still love it.