Speaking of Mile Davis, I think that 'Kind of Blue' is a bit over rated, and over played. John Coletrane from that same era on the other hand is quite good.
In my opinion, Miles Davis was at his most interesting period when in his electric phase, starting with 'Bitches Brew'. I fairly fond of ' On The Corner', 'Live Evil', and 'Dark Magus'.
As far as really outlandish Jazz, though, you'll probably want to stay away from Sun Ra as well as Peter Brotzmann, Jaap Blonk, etc...