The list order is based on repeat plays:
The Searchers
The Horse Soldiers
Major Dundee
The Missing
The Three Burials Of Melquiades Estrada
Lonely Are The Brave
Seraphim Falls
Fort Apache
Will Penny
Hud
Dance With Wolves
Open Range
True Grit (both)
The Lonesome Dove
Broken Trail
The Alamo (orig)...
Finally, many posts in and someone has mentioned Major Dundee, certainly in my top five. Those that have not seen it are missing a lot. Come to think of it has anyone mentioned The Missing from 2003. I'll put together my list ASAP.