Mmm would have thought The Proposition would have made the list. While I'm sure technically it isn't a western... I think it captured the feel of a western and is up there at the top of my list as far as the 'Western' genre goes. Also on my top ten list for movies.
Brilliant, dark and chilling film. Well acted by the cast, well written by Nick Cave and beautifully directed by John Hillcoat, a director who's gone a little under-acknowledged by most which is a shame given the quality of his few films. Also the film as one of the most chilling and beautiful scores that sets the whole movie, which was also written by Nick Cave along with Warren Ellis.
I think it's a crime that such a film is so under acknowledged by even western fans never mind the general public. I guess it's a little dark for their taste. Though Bob didn't seem to like Hillcoat's other film "The Road" so maybe he's just not a fan.
Still I can't recommend the film enough. I love this film above the other westerns I've watched. I know I don't have an internet show and probably no reason for anyone to trust my judgement or recommendations but I recommend it none the less.
Edit: Thinking of RDR... I'm sure that game took some influence from the proposition. I mean, the whole kill your mates to save your family bit seemed similar to the whole kill your brother to save the other one in Proposition. Also when meeting with his former leader and friend... there relationship seemed similar to Charlie and Arthur Burns. Though the game took influences from the spaghetti westerns... I'm sure the game also referenced The Proposition and Unforgiven here and there.