Best Stereo Upgrade Value

I'd probably agree with every single post on this thread dependent on exact time and situation of system at that time, this means weak or squeaky link gets the grease.

Distributed bass array.

Speakers first, mono amplifiers second, pre amplifiers third.  All other changes are like adding sprinkles to an ice cream cone, nice but could live without.

Rather than spending big bucks on what I think the weakest link is (and buying again and again), it’s probably best if I just play with the “environment” (angles, walls, etc.) for a while and maybe I’ll find out that unless I want to spend some really big bucks and upgrade everything, then possibly I’m near the best I’ll get…for my ears (at least). 

That is a sage plan.

I like the last two comments and agree with the recommendation (angles before $$$!).  It's all about "value"...what's the biggest bang for the buck; maybe starting with the weakest link (if you know what it is!).