Best possible PA setup

It's a topic that lends itself to heated arguments. :pac: Microphones go into preamps, preamps go into poweramps, and poweramps go into speakers, but anything after that is debateable.

There is no "best". A PA system can be optimised to the performance or performer being engineered and/or it can be optimised to the space it's placed in. A good venue is optimising for the space and then pitching generally towards the type of performance that's expected in the venue. You don't need 800 watt subwoofers foh for a singer/songwriter night etc. A touring band PA does the reverse - you design it to suit the band and ensure it's generally capable of suiting the type of venues you'll be in. But even so, optimising is to the ears of the person setting up the system. Lots of venues/engineers like to have bottom-heavy gain structures. I prefer to aspire towards linearity, no matter the venue or musical style, which requires a lot less power in the subwoofers. But then, I quit live engineering because it makes me crazy mad.