Last week I ordered from Amazon the 3-disc boxed set "Gunsmoke, the Director's Collection", which contains 15 episodes from that great TV show. Expect to receive it this week so that'll probably be the next Western I watch.
Inasmuch as Westerns were probably the favorite film genre of all time (at least it was mine), I'm kinda surprised that the entertainment industry hasn't begun marketing more DVDs like "Gunsmoke". That show and "Bonanza" ran for about 20 years on TV so they have plenty of material to work with. I'd also like to see "Maverick" (with James Garner) and "Wanted Dead or Alive" (with Steve McQueen) on disc. "High Chapparal" was another pretty good Western on TV.