Best song for immediate impact when presenting or testing?

I sold a ton of Magnepan and Audio Research products back in the day with both "Money" (Pink Floyd) and "Midnight at the Oasis" (Maria Muldaur).

Linda Ronstadt was also a hit--as she should be, of course, as was the Lincoln Mayorga series of direct-to-disc recordings.  I would actually suggest them (Mayorga) for ANYONE listening critically to a system before purchase.  GIGO and buyer beware!

Cheers!

"Book of Shadows" from Black Light Syndrome.
Features - Terry Bozio, Tony Levin and Steve Stevens - Jazz/Fusion. It's a masterpiece.

N

Dave Brubeck’s “Take 5” is an extraordinary recording when played on a decent Hi-Fi, and it was recorded 60 years ago! The song is effectively a drum solo and that drum solo on the left speaker and the sax straight down the middle at the start and end of the song will give you so much info on the capabilities of the system.

Elvis’ “Fever” from the Living Stereo RCA master is an amazing vocal recording. It should be warm and present in the room.

John Martyn’s “Easy Blues” from the Solid Air album has a brilliant into piece of acoustic guitar - all dynamics and heavy plucking.

I had a lot of fun listening to the first half of this list last night!  In particular the 17-minute Dave Holland track melted my face into a puddle on the couch.  Weather Report surprised me by holding my attention for 7+ minutes of fairly "out" sounds.  And I'd never even heard of Malcolm Arnold (classical isn't my wheelhouse) but the Keith Johnson recording was typically sublime.

When I'm demonstrating the system to someone uninitiated, I explain that we'll progess like a wine or beer tasting -- simpler fare to start, palate-wreckers at the end.  So I'll lead off with Getz/Gilberto "Girl from Ipanema."  They all know the song; it soothes the ears and the mind. A couple of minutes into the track, when Stan starts to blow, they're usually hooked.  

After that I might toss out mid-tawdry chestnuts like 
Paul Simon -- Rhythm of the Saints -- "Can't Run But"
Muddy Waters -- Folk Singer -- "Country Boy"
Sonny Rollins -- Way out West -- "I'm an Old Cowhand"
Steely Dan -- Gaucho -- "Babylon Sisters"

Once I've connected on any of these, I'll just hand them the iPad and let them drive to their heart's content.  They'll eventually play their favorite Black Keys track, then look at me with sad eyes to ask why it sounds so bad.  We'll talk for a minute about dynamic range compression.

We might eventually bring the house down with something like
Sara Bareilles -- Brave Enough -- "Goodbye Yellow Brick Road"
Yes -- Fragile -- "Heart of the Sunrise" or
The Bad Plus -- Give -- "1979 Semi-Finalist."