Here is a loosely organized overview of ambient music featuring some notable artists and releases. Huge thanks to this sub's ambient community and the book Ambient Century by Mark Prendergast which were extremely helpful putting this together.

Composers

• Erik Satie - Gnossiennes (1893) - Trois Gymnopédies (1888)
• Claude Debussy - Images Pour Orchestre: II Ibéria b. Les Parfums de la Nuit (1905-8) - Nocturnes I Nuages (1892-9)
• Gustav Mahler - Symphony No. 5 in C-Sharp Minor: IV Adagietto (1901-2)
• Maurice Ravel - Pavane pour une infante défunte (1899) - Ma Mère l’oye - Pavane de la belle au bois dormant (1908-10)
• Frederick Delius - On hearing the first cuckoo in Spring (1912) - Irmelin Prelude (1890-2)
• Charles Ives - The Unanswered Question (1908)
• Charles Griffes - The Kairn of Koridwen (1916)
• Albert Ketelbey - Sanctuary of the Heart (1924)
• Fats Waller - Water Boy, The Lonesome Road, from At The Organ (1926-39)
• Olivier Messiaen - Turangalila Symphony: VI Jardin du sommeil d’amour (1946-8)
• John Cage - Dream (1948), In A Landscape (1948), Nocturne, (1947)
• Ravi Shankar - The Sounds of India (1957)
• Miles Davis - Kind of Blue (1959), Bitches Brew (1970), In A Silent Way (1969)
• György Ligeti - 2001 Space Odyssey Soundtrack (selected tracks) (1968)
• Morton Subotnick - Silver Apples of the Moon (1967), The Wild Bull (1968)
• Alice Coltrane - World Galaxy (1972) - Illuminations (1974)
• Wendy Carlos - Clockwork Orange ost (1971), The Shining ost (1980), Tron ost (1982)
• Morton Feldman - Triadic Memories (1981)
• Toru Takemitsu - Rain Spell (1982)
• Kaija Saariaho - Maa I. Journey (1991)

Tape & Recording Manipulation / Musique Concrète / Early Electronic

• Otto Luening & Vladimir Ussachevsky - Low Speed (1952)
• Karlheinz Stockhausen - Studie I (1953), Kontakte (1958-60), Telemusik (1966)
• Raymond Scott - Soothing Sounds for Baby (1962)
• Pierre Schaeffer - Volumes from Musique Experimentale 1 (1962)
• Daphne Oram - Pulse Persephone (1965)
• Pierre Henry - Le Voyage (1968)
• Mort Garson - Plantasia (1976)

Minimalism

• La Monte Young - The Well-Tuned Piano (1964)
• Terry Reilly - In C, Rainbow In Curved Air (1969)
• Steve Reich - Drumming (1971), Music for 18 Musicians (1976)
• Keith Jarrett - The Köln Concert (1975)
• Brian Eno - Ambient 1 Music for Airports (1978), Discreet Music (1975),
• Arvo Pärt - Spiegel im Spiegel (1978)
• Jon Hassell - Possible Musics: Fourth World Vol. 1 (1980)
• Philip Glass - Glassworks (1981)
• Harold Budd - The Pearl (1984)
• Pauline Oliveros - Deep Listening (1989)
• John Taverner - The Last Sleep of the Virgin (1991)
• John Adams - Hoodoo Zephyr (1993)
• David Toop - Screen Ceremonies (1995)

New Age

• Iasos - Inter-Dimensional Music (1975)
• KITARO - Silk Road series (1980)
• Laraaji - Ambient 3 Day of Radiance (1980)
• Michael Hedges - Aerial Boundaries (1984)
• Suzanne Ciani - Velocity of Love (1985)
• William Ackerman - Conferring With The Moon (1986)
• Andreas Vollendender - Down to the Moon (1986)

Rock/Prog/Metal

• David Bowie - Low (1977)
• The Grateful Dead - Dark Star (1969) - The Other One (1971)
• Pink Floyd - Echoes (1971) - On The Run (1973)
• Popol Vuh - In Den Garten Pharaos (1971) - Aguirre (1975) - Nosferatu (1978)
• Neu! - Im Glück (1972)
• Ash Ra Tempel - Schwingungen (1972)
• Tangerine Dream - Zeit (1972) - Phaedra (1974)
• Can - Future Days (1973)
• Robert Fripp - No Pussyfooting (1973) - Evening Star (1975) - Soundscapes Live Series (1994)
• Mike Oldfield - Tubular Bells (1973) - Incantations (1978)
• Harmonia - Deluxe (1975)
• Manuel Göttsching - Inventions for Electric Guitar (1975)
• Cluster - Cluster & Eno (1977)
• Steve Hillage - Rainbow Dome Musick (1979)
• Hans Joachim Roedelius - Wie das Wispern des Windes (1986) - Selbstportrait I, II & III (1979-80)
• David Sylvian - Gone To Earth (disc 2) (1986), Approaching Silence (1999)
• Bill Nelson - Chance Encounters In The Garden of Lights (1987)
• Holger Czukay & David Sylvain - Plight & Premonition (1988) - Flux & Mutability (1989)
• Peter Gabriel - Passion (1989)
• Spacemen 3 - Dreamweapon (1990)
• Earth - Earth 2: Special Low Frequency Versions (1993)
• Boris - Flood (2000)
• Sunn o))) - Monoliths & Dimensions (2009)

Synthesizer Music

• Tonto’s Expanding Head Band - Zero Time (1971)
• Klaus Schulze - Timewind (1975) - Mirage (1977) - Dark Side of the Moog series
• Beaver & Krause - In A Wild Sanctuary (1975)
• Kraftwerk - Autobahn (1974) - Radio-Activity (1975)
• Tim Blake - Radio Gnome Invisible Trilogy w/ Gong (1973-4) - Crystal Machine (1977) - Magick (1991)
• Jean-Michel Jarre - Oxygène (1976) - Equinoxe (1978) - Waiting For Cousteau (1990)
• Vangelis - Blade Runner Soundtrack (1982) - Soil Festivities (1984)
• Ryuichi Sakamoto - Merry Christmas Mr Lawrence (1983) - Esperanto (1985) - Cendre w/ Fennesz (2007) - Async (2017) -
• Robert Rich - Trances & Drones (1983) - Bestiary (2001) - Somnium (2001) - Filaments (2015)
• Steve Roach - Structures In Silence (1984) - Dreamtime Return (1988) - Soma w/ Robert Rich (1992)
• Haruomi Hosono - Paradise View (1985) - The Endless Talking (1985) - Medicine Compilation (1993)
• Hiroshi Yoshimura - Green (1986)

Electronic

• Art of Noise - The Ambient Collection (1990)
• The KLF - Chill Out (1990)
• The Orb - Adventures Beyond The Ultraworld (1991) - U.F.Orb (1992) - Orbus Terrarum (1995)
• Pete Namlook - Silence (1992) - 2350 Broadway w/ Tetsu Inoue (1993) - Air (1994)
  
• The Irresistible Force - Flying High (1992) - Dreamfish 1 & 2 w/ Pete Namlook (1993-5) - Global Chillage (1994)
• Thomas Köner - permafrost (1993)
• Global Communication - 76:14 (1994)
• Future Sound of London - Lifeforms (1994)
• Aphex Twin - Selected Ambient Works Vol. 2 (1994)
• Bill Laswell as Axiom Ambient - Lost In The Translation (1994)
• Woob - 1194 (1994)
• Tetsu Inoue - Ambient Otaku (1994)
• Biosphere - Substrata (1997)
• Boards of Canada - Music Has The Right To Children (1998)
• Susumu Yokota - Sakura (1999)
• William Orbit - Pieces In A Modern Style (2000)

21st Century Indie ambient & Modern favorites

• Sigur Ros - Von (1997) - Ágaetis byrjun (1999) - () (2002) - Takk… (2005)
• Gas - Pop (2000)
• Raison D’Etre - The Empty Hollow Unfolds (2000)
• Fennesz - Endless Summer (2001)
• Keith Fullerton Whitman - Playthroughs (2002)
• William Basinski - The Disintegration Loops I-IV (2002-3)
• Tycho - Past Is Prologue (2004) - Dive (2011) - Awake (2014)
• Carbon Based Lifeforms - World of Sleepers (2006) - Interloper (2010)
• Stars of the Lid - And Their Refinement of the Decline (2007)
• Alio Die - Aura Seminalis (2008)
• Loscil - Endless Falls (2010)
• A Winged Victory for the Sullen - Self Titled (2011)
• Tim Hecker - Ravedeath, 1972 (2011)
• Grouper - A.I.A Alien Observer (2011)
• C418 - Minecraft Volume Alpha (2011)
• Olafur Arnalds - Living Room Songs (2011) - Re:member (2018)
• Hammock - Departure Songs (2012)
• Nils Frahm - Spaces (2013)
• State Azure - So Long Eternity (2013)
• Phobium - Oort Cloud (2013)
• Kassel Jaeger - Toxic Cosmopolitanism (2014)
• Max Richter - Sleep (2015)
• Kaitlyn Aurelia Smith - Ears (2016)
• Ian William Craig - Centres (2016)
• Huerco S - For Those Who Have Never (And Also Those Who Have) (2016)
• The Caretaker - Everywhere at the End of Time (2016)
• Carmen Villain - Infinite Avenue (2017)
• Sarah Davachi - Let Night Come On Bells End The Day (2018)
• Skee Mask - Compro (2018)
• Anna Roxanne - Because of A Flower (2020)
• Flora Yin-Wong - Holy Palm (2020)
• Mary Lattimore - Silver Ladders (2020)
• Ulla - tumbling Towards A Wall (2020)
• KMRU - Peel (2020)
• Music for Space travel - The Space Cadet (2021)
• Hilyard - Division Cycle (2021)
• Siavash Amini - A Trail of Laughters (2021)
• Nala Sinephro - Space 1.8 (2021)

r/ambientmusic Top 10 ambient albums of 2022

• 36 & zakè - Stasis Sounds for Long Distance Space Travel II
• Sofie Birch - Holotropica
• Blood Incantation - Timewave Zero
• Sarah Davachi - Two Sisters
• Nils Frahm - Music For Animals
• Locrian - New Catastrophism
• Claire Rousay - everything perfect is already here
• Ulla - Foam
• Carmen Villain - Only Love From Now On
• Warmth - The Night

r/ambientmusic Top 10 ambient albums of 2023

• 12 by Ryuchi Sakamoto
• Atlas by Laurel Halo
• Colours of Air by Loscil // Lawrence English
• Crépuscule I & II by Tujiko Noriko
• Forgotten Melodies by The Space Cadet
• Headlands by Fog Net
• Mycelium Music by Matthewdavid
• New Blue Sun by André 3000
• The Notional Pastures of Imaginary - Softwoods by Imaginary Softwoods
• Signs by Purelink