+1 @knotscott
I took your question to mean building a system, so I would answer absolutely
the speakers and the speakers........
With the room a close second.
Regards,
barts
And the biggest influence on sound quality is...
The quality of the recording itself.
Then the room, the setup, the speakers, and lastly the front end.
I've got recordings that make my system sound horrible, and I've got recordings that make my system sound absolutely wonderful.
None of the gear changes have had that much impact on sound quality.