I listen to 3 genres that are a large portion instrumental.
Those being: prog, jazz, and contemporary classical, so I could list pages.
Jazz:
My favorite all time single instrumentalist, is probably guitarist Allan Holdsworth. Not only was his technique advanced, but his entire approach to playing was revolutionary.
McCoy Tyner - pianist / Terrifying chops, and creative.
Chick Corea - keyboardist / Chops and creativity to spare.
John Coltrane / Not much needs to be said here.
John McClaughlin - guitarist / Technique and emotion. Leader of the best, IMO, fusion band, Mahavishnu Orchestra.
Jaco Pastorius - bass / Innovator, chops.
Hiromi - Killer Japanese keyboard player.
Alex Machancek - guitarist / Contemporary fusion player with great chops, and composes quite complex stuff.
This is really tough, not because it is hard to think of that many, but because there are so many I would place at near equal levels.
Jazz groups:
Mahavishnu Orchestra
Return to Forever
Brand X
Weather report
Pnazerballett
Steve Coleman and the Five Elements
Oregon
Iceberg