Disregarding the usual John Williams recommendations and the usual big names (Horner, Elfman, Zimmer, etc.), my three favorite and probably most underrated composers are Ennio Morricone, James Newton Howard and Basil Poledouris. Morricone's work on spaghetti westerns and The Untouchables is unforgettable, Howard's score for Unbreakable is my favorite of the past decade and Poledouris clocked in some of my all-time favorites with Conan The Barbarian, Quigley Down Under, RoboCop and The Hunt for Red October. The score to Conan the Barbarian alone should put him in the same league with all-time greats.