A lot of what I said of Human Nature applies here.  The writing is solid, the cast and characters are great, and this episode in particular has a very strong look and feel to it.  Sure, the scarecrows can be a bit goofy, but the Family of Blood and their unique mannerisms more than make up for that.  The Doctor returning is a big moment here that leads to an even bigger moment when he defeats the Family of Blood.  The way he stops them is such a show-stopping moment, too.  It is a now legendary ending for any Doctor Who episode and, in my opinion, The Family of Blood is a masterpiece.  A truly creative and meaningful work of art I very much enjoyed and has held up on every re-watch since.