Of those nominated for Best Picture that did NOT win Best Picture, here are my favorites (I am only listing movies I score a 6-6.5/10 or higher)...
-La La Land (2016)
-Nebraska (2013) (this is also my #1 movie of 2013 straight up and within my Top 102 movies in general)
-Django Unchained (2012) (easily the best movie of the nominee's and within my Top 102 movies in general)
-The Descendants (2011) (within my Top 52 movies in general and easily the best movie of the nominee's)
-True Grit (2010) (within my Top 52 movies in general and easily the best movie of the nominee's)
-Up in the Air (2009) (within my Top 52 movies (or not much outside of my Top 21 movies). it's easily the best of the nominee's)
-Juno (2007) (within my Top 102 movies and easily the best of the nominee's)
-Munich (2005) (within my Top 52 movies (or not much outside of my Top 21 movies). it's easily the best of the nominee's)
-The Aviator (2004) (and Sideways (2004)) (The Aviator is within my Top 102 movies and it's my #1 of the nominee's as only Sideways (within my Top 189 movies) is even a slight challenge to it)
-Gangs of New York (2002) (within my Top 189 movies (or not much outside of my Top 102 movies). it's easily the best movie of the nominee's)
-The Green Mile (1999) (within my Top 52 movies (or not much outside of my Top 21 movies). it's easily the best movie of the nominee's (and I am sure it's got the most mainstream appeal to of the nominee's this year))
-Good Will Hunting (1997) (within my Top 21 movies. it's easily the best of the nominee's this year)
-Jerry Maguire (1996) (within my Top 21 movies. it's easily the best of the nominee's this year)
-Pulp Fiction (1994) (while Forrest Gump is a solid movie, Pulp Fiction is clearly superior in my mind as Pulp Fiction is within my Top 21 movies straight up where as Forrest Gump is within my Top 189. also, Shawshank is within my Top 102 movies.)
-The Godfather Part III (1990) (within my Top 102 movies and my #1 movie of the Godfather trilogy. easily the best movie of those nominated this year)
-Apocalypse Now (1979) (within my Top 52 movies and easily the best of those nominated)
-Butch Cassidy and the Sundance Kid (1969) (within my Top 102 movies and easily the best of those nominated this year)
-The Hustler (1961) (within my Top 21 movies and clearly the best movie of those nominated this year as I highly doubt had I seen the rest that they would even come close to this)
-The Song of Bernadette (1943) (within my Top 189 movies and I doubt anything else, had I seen the rest, challenge this one. for the record... I have only basically seen this one and attempted to see Casablanca but could not finish it due to boredom)
so basically... strictly looking at the movies nominated in those years listed above I would have given the 'Best Picture' Oscar to those movies if it were up to me simply because those movies are just the most all around enjoyable to watch and re-watch as the years pass.
That's the truth right there.
with that said... they still nominate quality movies here and there but most of the time they don't even nominate the quality movies in a given year. but politics definitely take priority over the rest, especially in fairly recent memory.