Soul music and Jazz music are the main ingredient. But when i'm feeling adventurous I like to try New Age or ambient (Enya type piano music, celtic music, neo-classical etc). or some like French accordion music, or some cheezy Kenny Loggins/Michael Mcdonald era 'yacht rock' and 'easy listening' records have good cuts in the slower songs. Sad folk music, particularly with female vocals can have some real gems. I also think about all those 60s psychedelic bands in the style of the Beatles, the Who, the Beach Boys, the Zombies who experimented with sounds and recording techniques.. Oh and Soundtrack scores. particuarly from the 1960s-1980s.John Barry, Ennio Morricone etc.
Jazz is bread and butter. It's very rare I touch Soul music, because everyone does it and most of it is sampled already. I started out doing Soul, but quickly went with Jazz. I like Latin music and obscure soundtracks as well. And Japanese of course.
It varies depending on what mood im feeling, but usually it ranges between slower 70s funk/soul jams. There are the occasional times I would chop up and flip industrial noise tracks when I want to experiment outside my comfort zone.
I like sampling spoken word stuff, sometimes it's cheesey dialogue from movies, sometimes just random stuff. Recently I took a line from a Ronald Reagan speech and built a house track around it. It was fun