I feel like an asshole for not mentioning Buckethead in my list. I mean, he does a lot of straight forward stuff, but he's mostly Avant-garde and experimental. Hell, he's the reason I delved deeper into the genre and found Unexpect.
SHIT.
How did I forget him? The man's a genius, plain and simple.
Honestly, if you want his most avant-garde stuff from that list, I'd say go with Inbred Mountain. If you want a more straightforward album, go with Albino Slug. If you want something completely out of this world and weird, go with Bucketheadland 2, and if you want a cool album with some forgettable tracks (but with many amazing ones), go with Monsters and Robots.