I bought it just last weekend and really liked it. I already own Barton Fink, The Big Lebowski, The Man Who Wasn't There, Fargo, and O Brother Where Art Thou, so I figured "why not."
I meant to see it in the theaters but didn't. Did see There Will Be Blood. Having not seen NCFOM prior to the oscars, I was shocked that TWBB didn't win best picture...more shocked PT didn't get best director. However, after seeing it, I can see how it go best picture...but I'm still stumped on the best director. The Coen's always bring a certain touch to the direction of their films, even down to being involved with the cinematography, color correction and look of the film. NCFOM was definitely well directed and looked beautiful, but TWBB was still better in my mind in terms of directorial accomplishment.
I enjoyed NCFOM and am certainly glad I purchased it on DVD. I'm sure I'll watch it more than once.