MD is the hardcore 16-bit freak's paradise.
So many really good unheralded games.
Here's one fool's list:
Assault Suits Leynos (fucking hard, brilliant music, good control that takes patience. EGM ripped it for being too hard as Target Earth.)
Devils Crash MD (better than the PCE rev, thanks to some sweet reworked tunes courtesy of Technosoft. Better bonus rounds too...)
Dodge Danpei (ferocious dodgeball action that beats anything by Technos. Great use of a manga license, wicked control and music.)
Those are some of my sleepers, since everyone has already well-covered the established faves listed. ThunderForce series rates truly high with me, still possibly my fave shooters ever. Right up there with Compile's work.
I still dream at night of the wonders TechnoSoft could have crafted on the Neo-Geo with it's wicked palette, scaling/rotation/sprite handling, and lethal sound chip. ThunderForceNeo will always be my glimmering wet gamer's dream.