Just going through my album collection here...

Tool - Lateralus
The Trainspotting soundtrack - I believe I gushed about it in another thread, it's basically designed to get stoned to, as long as you skip Sleeper's "Atomic"
Any Shpongle album, particularly Nothing Lasts, where the bird sounds at the beginning always make me look around to try and find them
Humus Conspiracy - mixed by DJ Yaniv, a compilation of various psychedelic artists that maintains the same dark beat for over an hour, which is great for going for a walk high
Vangelis - the Blade Runner soundtrack - nice and mellow, and the quotes put my mind onto interesting tracks. It's trippy when it all of a sudden hits the 1930's-ish "Stormy Weather" after so much ambient jazz
Cascada - Everytime We Touch - I don't usually go for pop-techno, but most of the tracks on this one just makes me want to get up and dance like crazy
Nine Inch Nails - The Fragile
Any album by Carbon Based Lifeforms - great ambient space stuff, but try not to get paranoid while listening to this, it gets fucking scary
Chumbawumba - Tubthumper - I've been listening to this album since it was released and for some reason it's still not old for me