You can't go wrong with some Buckethead. Unfortunately, the man has released at least 30 albums, generally with a few great tracks mixed with a few more not great tracks. You might be best off making a custom playlist on YouTube or something. Songs I'd recommend for a Bucketnewbie: "Soothsayer", "Jordan", "Frozen Brains Tell No Tales", "Whitewash" and "Brewer in the Air".
Lately though, I've been listening to two of Carcass' albums, namely "Heartwork" and "Necroticism". I'd recommend the tracks "Heartwork", "Incarnated Solvent Abuse" and "Corporal Jigsore Quandary".