Responses from worldwide

Tube Friendly High End "Big" speakers
Tannoy Prestige. 
Parasound A21 vs Bryston 4bsst 2
Bryston hands down. 
Help me with a simple pre/pro challenge please?
Outlaw, Emotiva, anything used on Agon. 
going backward to inwalls - some questions
Would the speakers generally be pointing at your listening position? If so I don't see a problem. As for subs, look at Triad or Wisdom Audio or James Loudspeaker. 
Best imaging and sounding bookshelf speaker
Genelec 8050, psi a21m, quested v2108. All will play loud with no compression and blow away anything mentioned here. 
Audiophile Active Speakers?
Floor standers, try,Psi audioKs digital 
Subwoofer to match my B&W 601s2,CC6s2 and DM600i
I'd go with a sub from Outlaw Audio. 
Must L + C + R speakers be depth-aligned?
Bad idea to wall mount speakers. You'll get all sorts of reflections from the front wall around the speakers. Better to flush mount. 
Inexpensive wall mount speakers
Check these out. 
Speaker Upgrade Help Please
How about in-walls? Dali makes an awesome in wall. Triad also make great in-walls. Also Wisdom Audio. 
Speaker Upgrade Help Please
Adam S3X-V or Quested V3110. Either of these will be more dynamic and have a much greater SPL with no compression. Absolutely stunning. Also both are three ways. 
Looking for a high-quality 2-way speaker
2 ways: Quested v2108, Genelec 8250, Event Opal. 3 ways: Quested v 3110, Adam S3X-V, Neumann KH 310Any of these will blow away everything suggested in this thread. 
I wanna rock -- with monitors on stands
Go active with Quested V2108 or Genelec 8250 
Best Bookshelf speaker 1300.00 budget
Bookshelf speakers should be sealed, and I would recommend Quested S6R. 
Eggleston Works Dianne vs. Proac Response D18
Thanks. I've owned other Proac models that I liked.