Video game soundtracks and electronica can make some great background thinking music.
soundtrack to vvvvvv
portal (I might have bought this on a CD)
crystal method
wintergaten (that marble machine guy)
Epic soundtrack music. I.e. Two Steps From Hell, audiomachine, Celldweller
oh, I forgot about two steps from hell / Thomas Bergersen (he has a lot of stuff under just his name). I’ll tick on E.S. Posthumus, don’t know if they have any movie music, but they certainly have the epic soundtrack style. x-ray dog is another one of the companies that puts out tons of soundtracks.
I’ll have to give those others a listen.
Whatever comes up from the search term “lofi house”. Long compilations of good, uncomplicated, ethereal-sounding music that let me go on for hours without having to interact with the player. EATEOT is surprisingly good for this too, especially if you need your mood to do a 180° really fast.
I listen to the Lo-Fi Girl playlists on Spotify.
soma.fm has several stations that are really just rhythmic ambient noise. I think it works great when I need my brain to enter a zen mode so I can work despite my ADHD. If I listen to good music I like, I’ll keep getting distracted and if I listen to nothing at all then I can hear every noise my neighbors make and it distracts me similarly.
Music for Airports by Brian Eno