What's your favorite boutique speaker maker

Carl Marchisotto/ Nola speakers. 

Viking Acoustic in Sante Fe.  The difference between a boutique company and a well known brand is the personal relationship that you receive with the boutique company.  I ordered a pair of Grande Voix speakers from David Counsell who is the owner of Viking.  You get to design exactly what you want and then you have ongoing discussions during the build process.  It also helps to have a master cabinet builder.  

+1 for Salk!  I love my Supercharged SongTowers!  I worked directly with Jim through the selection and build process - he sent me pictures of my speakers being built at various phases of construction and was extremely responsive throughout the process (and years later when I sought advice on hardware to reattach the plinths after the original bolts were lost in a move!).

I ended up with a gorgeous pair of hand built speakers that I've been enjoying for 7 years now - they continue to improve as I upgrade all of the other components in my system (currently simplified to an ELAC DDP-2 for streaming/playing files stored on a NAS feeding via XLR an older 3 channel Krell amp where I'm only using 2 channels).

To my ears they are very detailed without being harsh or fatiguing in any way, image to the point that you sometimes feel like you're awkwardly staring down the throat of vocalists and can precisely and separately identify different instruments in space, and have surprising bass extension and weight for the driver and enclosure size.

I also purchased a matching 15" sub built at the same time that Jim fabricates using Rythmik electronics.  When properly dialed in to match the mains, the combination is enthralling!

Simon Mears Audio.

Of note: quite a few speaker brands mentioned here that have nothing to do with "boutique." Let's sharpen them pencils, please. 

I took a look at Simon Mears Audio and boutique they are. Not to my taste but I imagine they sound wonderful.