http://www.ektoplazm.com/style/psy-dub
http://www.ektoplazm.com/style/downtempo
http://www.ektoplazm.com/style/deep-trance
http://www.ektoplazm.com/style/ambient
Should keep you busy for quite a while
Unfortunately you can't restrict it to compilations only though.
Edit. Some recommendations from my collection. Some of these can be quite damn hard to find.
Grouped by label.
Aleph Zero Dark Room Beats Digital Singles Vol. 1 Digital Singles Vol. 2 Midnight Soul Dive Natural Born Chillers Natural Born Chillers 2 Altar Records Air Water Fire Earth Ether Native State Records Beneath the Surface Bioluminescence Left Coast Liquid Vol. 1 Electrik Dream Cosmik Chill Orange Cosmik Chill Red Liquid Sound Design Butterfly Dawn Mana Medicine Elucidations Spiral Trax Ease Division Ease Division 2 Ease Division 3 Ease Division 4 Twisted Records Eclipse Sofa Beats / Iboga Floating Point 01 Floating Point II Floating Point 3 Floating Point 4 Hadra Hadravision TIP Records / TIP.World Infinite Excursions Infinite Excursions 2 Infinite Excursions 3 Twelve Blue Hour Sounds Made of Dawn Chapter One Electronic Soundscapes Polymorphic Convolutions Organic Records Psymeditation Psymeditation 2 Chill Tribe Ear Pleasure Relaxed Journeys Quality Relaxation Peak Records Chilling Goddess Chillogram Tranchillizer
