Boards of Canada, beautiful lunar landscape, Braving the glacier, airplanes over johannesburg, 65daysofstatic, oceans, explosions in the sky, the Kilimanjaro darkjazz ensemble, mogwai, tortoise,
Varying levels of "ambient"/"post rock" there, but I tend to listen to this stuff at work, as well as a bit more trance stuff if I want something a bit more up beat, so some of the trance "best of albums" like the platipus compilations.