Carter - Changes
Takemitsu - All in Twilight
Henze - Drei Tentos from Kammermusik
Ferneyhough - Kurze Schatten II
Falla - Homenaje
Man there are so many...,.i love all the pieces you've mentioned already so I'll pick some different ones (I really can't pick just 5!)
Solo guitar
Brouwer: Sonata
Giuliani: Grand Overture
Carter: Shard
Koshkin: The Prince's Toys
José: Sonata
(Honourable mentions go to Mertz's Fantaisie Hongroise, Richard Charlton's Threnody for Chernobyl, variations on a 12-tone theme, Sor's Grand Solo, Villa-Lobos's 12 Études and basically just all of Brouwer's solo music!)
duos, trios, quartets
Piazzola: Tango Suite
Sor: L'Encouragment
Brouwer: Cuban Landscape with Rain
Phillip Houghton: Three Duets
Kleynjans: Oceano Nox
concertos
Brouwer: Concerto No. 3 'Concierto Elegiaco'
Takemitsu: To the Edge of Dream
Rodrigo: Concierto Madrigal
Giuliani: Concerto no. 3
Villa-Lobos: Guitar Concerto
(And I'll squeeze in one more)
Castelnuovo-Tedesco: Concerto no. 1
Nocturnal by Britten.
There are a number of works listed above that I do not even know so I will have to investigate them.
One work that I will throw into the mix which would definitely be in my top five is Concerto Antico by Richard Harvey....
(http://ecx.images-amazon.com/images/I/71H4z13kVNL._SY355_.jpg)
....a wonderful work and definitely worth a listen if you do not know it.
Off the top .. BACH is the summit, super human technique required, yet highly musical, together, lyrical ..
other than that I do love Dowland, and Albéniz's Asturias arr.; Rodrigo's Concierto de Aranjuez.
Tarrega - Recuerdos de la Alhambra
Brouwer - Elogio de la Danza
Barrios - La Catedral
De Lucia - Cepa Andaluza
Tarrega - Adelita
Kyuhee Park has an incredible recording of the Brouwer sonata. There is also this stunning performance on youtube: https://www.youtube.com/watch?v=ZapPlB3a444