Mines a mess at the moment...What I tend to keep in it though...
Drum hits - Loads and loads and loads of them.
Drum loops - bits of live drumming and a few really nice bits like some of the DSC stuff and the Chris Vrenna ones from CM. Also a few very basic 1 bar kicks and hats for chucking in when I'm creating synth patterns and can't be arsed loading a sampler.
Guitars - Lots, nicked from all over. And stuff I've played (or particularly my mate who's shit hot at making nice sounds on guitar but can't ****ing play in time.) cut into loops.
Multisamples - loads of basses 'cos I love putting these into acid and painting in note by note almost tracker stylee
Few vocal snippets.
Loads of FX noises and drones and feedback from my ceaseless pissing about...