Dates covered are mid-1983 through 1996. I didn't start using stars until late 1989, so ratings for movies older than that have been added after the fact. Also, I did not write as many reviews as Siskel & Ebert. These are NOT the only western movies, or the best western movies, to come out during this period; they're just the ones I have reviews for.
BACK TO THE FUTURE, PART III. 
(A western for part of the time.)
DANCES WITH WOLVES.
DESPERADO. (I know this isn't REALLY a western in the temporal sense, but it looks so much like one I had to include it.)
LEGENDS OF THE FALL. 
QUICK AND THE DEAD.
RETURN TO SNOWY RIVER.
RUSTLERS' RHAPSODY. 
SILVERADO.
SOMMERSBY. (Not a traditional "western," but the temporal setting is right.)
TOMBSTONE.
WYATT EARP.