For me – I listen to George Winston’s “Winter” piano CD all year long. As for guitar, I seem to listen to Mason Williams’ “Classical Gas” as played by Tommy Emmanuel a lot.
But I don’t own a lot of instrumental music, so I’m eager to hear responses.
Don’t have much of this in my collection, either. But check out “Dee” on Ozzy Osbourne’s/Randy Rhoads’ live album Tribute.
I seek out solo piano pieces by jazz players like Art Tatum, **Red Garland ** and **Thelonious Monk ** - don’t have the song names off the top of my head.
Guitar - have you seen **Brian Setzer ** do Sleepwalk? Most efficient guitarist with is picking hand I have ever seen - alternating between finger and flatpicking…oh, and the music is sublime…
Link here: http://www.youtube.com/watch?v=ZZuHREUIVz8&feature=related - starts with rockabilly/country picking then slides into Sleepwalk…
I never get tired of Beethoven’s piano sonatas. I know the Moonlight is a cliche, but I don’t care - still love it.
Piano - Chopin, Ballade in g minor, op. 23, with honourable mentions to Lizst Years of Pilgrimage - Switzerland, the Brahms solo piano music recorded by Radu Lupu, and Earl Hines plays Ellington. (Hey, if you got to list a whole CD, why can’t I mention more than one? Do you have a favourite child?)
Guitar - this is killing me! Cherokee played by Joe Pass on ‘Sophisticated Lady’, though I could mention just about anything else by him, by Bucky Pizzarelli, George Van Eps or Gene Bertoncini. And classically, Manuel Barrueco playing anything by Leo Brouwer (particularly ‘Cancion de Cuna’) or Villa-Lobos.
Sorry, but that’s as much narrowing down as I can manage.
Piano: Variations on the canon by Johann Pachelbel on George Winston’s December CD.
I collect different versions of “Round Midnight,” so that would be my answer for both. Monk recorded the song several times, and I have a couple of him on solo piano, and my favorite solo guitar piece is Wes Montgomery’s.
Piano: Gershwin Plays Gershwin: The Piano Rolls, Complete Piano Rags by Scott Joplin, Louis Moreau Gottschalk: Piano Music, and Liszt Masterpieces for Solo Piano.
Guitar: I’m with Le Ministre on Bucky Pizzarelli (and his boy John), Albert Lee, and Frank Vignola.
I like a lot of the early Windham Hill piano stuff, including George Winston’s. If you like him, check out Scott Cossu and Jim Brickman; William Ackerman has a lot of great Windham Hill guitar tunes.
Erik Satie’s Three Gymnopedies is an elegant, spare piano composition that’s long been a favorite of mine.
Good lord, yes - I have Virtuoso #3 by Joe Pass (an album of solo guitar pieces by him) and am :smack:'ing myself for not thinking to mention it earlier. Amazing, amazing stuff.
Faves: Fats Waller, Handful of Keys; Dick McDonough, Honeysuckle Rose.
Guitar: Pierre Bensusan, “Reels: The Pure Drop/Flax in Bloom”
Two Irish pieces played in DADGAD tuning, just lovely.
Piano: Thelonious Monk, “Ruby My Dear”
Or, just as good, “I’m Confessin’” and “Round Midnight.” I love Monk’s ballad playing, and don’t really own much solo piano jazz.
Glenn Gould rates an honorable mention but the listening is spread out over a lot of pieces.
No single song, but I like Monk Alone quite a bit.
Guitar is harder to narrow down but there’s a John Williams album called Echoes of London that I like a lot, especially his rendition of “Streets of London.”
Piano: I haven’t listened to it in a while, but I always enjoy Mozart’s Alla Turca. I just love how it runs all over the piano.
Guitar: Lately, I’ve found myself listening a lot to Andy McKee’s Drifting.
Love Scott Joplin’s ragtime music.
Also love Chopin’s works, especially Fantaisie Impromptu.
Beethoven’s piano concerto number 5 “Emperor”, is an enchanting piece of musical genius.
For piano I really like Little Sister by Matthew Tavis Johnson. I can set up one of his albums on continuous play on my iPod and listen all day.
For guitar, my favorite is called Rain into Snow. I can’t remember the artist’s name on this one but if I ever become a good guitar player, I will learn to play this song.
Bach’s Goldberg Variations. Glenn Gould’s 1990 recording.
Mussorgsky’s Pictures at an Exhibition. Byron Janis, piano.
Beethoven Piano Concerto No. 4
And like LilShieste, I’m an Any McKee fan also. My favs are Rylynn and Art of Motion 
I’d love to hear that, recorded posthumously 
There’s two recordings by him, done in 1955 and 1981. The latter is the longer, more luxorious one and the one I prefer (and is perhaps the one you are referring to), the earlier one has a strong drive and insistency which is also absolutely riveting.
Chopin’s Nocturnes, particularly Op 9 No 1 & 2, and particularly Yundi Li’s and Arthur Rubenstein’s interpretations.