oddech_wymarlych_swiatow
for Wiz 1-5, best ports are indisputably the ps1 ports. options to change everything into English language, and also options to change all graphics and sprites to originals; or play with the "remake" ps1 polygonal graphics.
orchestral soundtrack(s) for the wiz 1-5 ports, on ps1, can't be changed however. In any case they are LOVELY to listen to. ps1 port's Wiz 4's full on trumpet/brass horn section-only OST is 100% BAD ASS.
for wiz 6, either play dos version (or NEC-PC) version, but if simply want ease-of-use play snes version via emulator. Snes versoin is content-identical, however it is slightly easier in that random encounter rate is reduced and also resting generates health and mana faster than in original version.
Keep in mind that even the DOS versions and the NEC-PC versions are "dumbed down"; only the Apple II original release versions feature original encounter rates and bullshit that was patched/fixed for the later DOS/etc releases. So even if playing DOS versions don't for a single second think you're playing the "hard-core" versoin.
only the apple ii versions may merit that distinction. However I recommend playing ps1 ports instead and actually having fun.
EDIT: if, for whatever reason, ps1 emu accessibility is not an option then by all means play the snes ports of wiz 1,2,3,5 and 6. Keep in mind, however, that UNLIKE THE ps1 PORTS, the snes ports feature tweaked encounter rates.
that said it's not like any version is actually easy. snes versions will kick your fucking ass, just like any Wizardry gam, if you don't know what you're doing.