The Fox duopoly of KDFW/KDFI in Dallas/Fort Worth used to be a pretty good one, a couple years ago, back when KDFI was an independent station. At the time, the station was fairly heavy on older syndicated shows (Perry Mason, Hawaii Five-O, Little House on the Prairie), many of which got pretty good ratings.
However, KDFI has steadily been turned into more and more of a dumping ground for third rate syndicated product that Fox has group bought. Between that and the fact that it's become a MNTV affiliate, it is a pretty pitiful station now.
Interestingly, some of the old shows that KDFI dumped to make group for third-tier court shows and the like are now running on KFWD, where they seem to be doing reasonably well. If nothing else, they're doing well enough to beat out the junk on KDFI.