This genre is currently packed full of good stuff. I got into more experimental productions having listening to Flying Lotus a few years ago who in my opinion sits at the very top of the tree. Within his records there is an obvious influence of hip-hop throughout, however the complex electronic bleeps, beats and baselines used as well as samples from anywhere and everywhere, make Flying Lotus very interesting to listen to.
The FlyLo track i've gone for features Declaime with some nice rhymes but it's all about the production of this track and the sampling used by Big Steve (he's actually huge..).
I recommend seeing this guy whenever you possibly can. Mindmelting.
For the old experimental record i was tempted to choose a Pink Floyd track (most probably selected from Dark Side Of The Moon) as it is one of my favourite albums ever.
However, i'm gonna keep things in the family. If you don't already know, FlyLo is the nephew of the late Alice and John Coltrane and as you can imagine, he grew up surrounded by amazing music. If you listen to more FlyLo material, you will see how this kind of material by Alice Coltrane has influenced the music he has made. I read that Alice free improvised on the Harp on this track which makes it so much better. Very experimental for the time of it's release (1970).