What should my next upgrade be? Your best experience

I have the itch to upgrade my system now that I've been in it for a moment. I mostly stream (Deezer) or listen to CD/SACD content. I occasionally play vinyl but rarely, I'm sure I will continue to grow into it but am not looking to improve the TT now. I listen to mostly Classic Rock, Jazz, Blues, and Indie music. I'm listening to Talking Heads (live acoustic) as I write this. The Marantz PM-11s3 has zero issues pushing the Monitor Audio Silver 8s, it actually is a little over kill for them I think, as it has complete control of them, never losing its composure.  So there is zero chance the PM-11s3 is up for replacement at this point.
The room is 14'x40' with 12' ceilings. The system has no issue filling every inch and at high volumes so no issue there.

Current system is -

Marantz PM-11s3
Marantz UD7007
Marantz TT-42 
Sonos Connect
Monitor Audio Silver 8's
Analysis Plus Purple Oval 12 bi-wire
Tributaries 8AB XLR (UD7007 to PM-11s3)
Tributaries 2A RCA (Sonos to PM-11s3)
CyberPower Conditioner

The obvious direction, it seems to me, is speakers? But am I missing something? Would upgrading to a real audio quality conditioner with an upgraded power cable give me something more and set me in the right direction for future upgrades? 
Or am I not where I need to be with cables? Can I make a sonic improvement by upgrading speaker cables and/or interconnects while again getting myself in a good position for future upgrades?
I have to admit that this is the best system I've had and I do love every minute of listening to it.... Its fast, accurate, and punchy yet it has great sound stage and its not clinical. It has that Marantz sound/charm (warm but not clouded).
I know posts like this are common and beaten to death but my system is unique as it is mine and probably not exactly like anybody else's...
Never-the-less, I know I'm nowhere near where most of you are! And I know for a fact I have much less knowledge than most of you. I'd like to keep bettering my system, moving towards the personal listening nirvana if you will. So what direction would you head in if you were in my shoes?