For me, it would probably be, 1. Once Upon a Time in the West 2. The Good, the Bad, and the Ugly 3. Unforgiven 4. The Long Riders 5. Ride the High Country Special shout-outs have to go to the original 3:10 to Yuma and The Fastest Gun Alive, which are two of my personal faves of the genre.
1. The Outlaw Josey Wales 2. The Good, The Bad, and the Ugly 3. The Fastest Gun Alive 4. Tombstone 5. High Plains Drifter