If we include SuperGrafx, we can include the 32X.
No you can't. 32x and PC-FX on the same level. Genesis/MD with PCE/SGX/SCD. An SGX is just a PCE with extra BG/sprites. A 32x has two additional 32bit CPUs, 2 additional should channels, and a whole new style video display with hicolor palette.
What part of Ys III have you seen that run into 15fps? None of the areas I tested were that low.
Valis III on MD is awesome. I was surprised they kept the cinemas on the cart. The music for the MD is great. PCE>MD but sometimes I'd rather play the MD 'cause I love the way music sounds (plus it's easy). (Played the Genesis version first)
Air Buster/Aero Blaster - tough call. I really like the MD music. MD>PCE 'cause of bigger sprites and music that just fits the MD. The PCE card is still great though (definitely a top list hucard). (Played the Genesis version first)
Ghouls 'N Ghosts - SGX>MD. Lots of reasons, but mainly... 'cause the tree's animation in the MD version look really ghey. (Played the Genesis version first)
Valis I - PCE>MD. I forget why, but it's just better. Something about the MD version I didn't care for. (Played the PCECD version first)
Forgotten Worlds - PCE>MD. The PCE port is nice, especially for an NEC port. The MD version looks like they didn't even try. A MD version with the same love they did with Strider would have been nice.
Strider - MD>PCE. Oh god, the ACD version sucks bad. Nothing to do with the static BGs, it just sucks. It fails from the many small details. Plus, that game is not originally from the release date it was released. I posted on this a while back.
Mercs - MD>PCE. Oh wait, they didn't port Mercs to PCECD. Too bad.
Ys III - PCE>SFC<MD. The music and cinemas give the edge, but mostly 'cause it was on TGCD and it was the first version I played. Even the crappy voice parts gave it an edge. I adored it when it first came out. The scrolling never bothered me back then and the parallax was certainly welcomed.
DS:LOH - PCE>MD. I'm just guess on this one. I really want to play through the MD version, though. I love the cutesy style gfx of the PCE version (looks like falcom style) over what I've seen on the MD version.
Devils Crush - PCE>MD. They could have just matched the PCE's res, but nooooo. The decide to "squish" the screen instead and add a side bar.