See, I would take The Father over Blackbird. I thought how The Father is presented was brilliant. During Blackbird, I just kept thinking "are we ending? Nope? Okay..."
Blackbird. Can't go wrong with either, but Blackbird will stay with you much longer. Frank Langella is giving a great performance as well - some members of the audience were deeply affected by it, as it reminded them of a parent or loved one.