Congratulations to Ohio State University law professor Doug Berman, who runs Sentencing Law and Policy; that blog has been cited over 20 times in court cases, according to Ian Best (3L Epiphany). Many (likely most) law professors never get that many court citations for all their law review articles put together, much less for their blog posts.
Ian also points to some other blogs that have been cited in court cases, but Sentencing Law and Policy is far ahead of any other.