as far as which is best... its not really a closable discussion. they all have thier strong points. imo it would be ideal to own all 3, snes, md and pce or at least emulate them.
i'm a md collector myself, i did own an snes which i was also starting to collect for but unfortunately it was lost to an ex
all 3 have games that are awesome, but have more that are shit.
who cares anyway, the amiga had the best games of that era