Barnabas prefers them pretty, submissive, gentle, kind and above all, young. I suppose because he "died" as a young man, he still looks for that youthful beauty, even though he himself looks older.
SPOILERS...
Roger likes women who mistreat him. He and Laura became husband and wife only because she supported (lied) about Burke's guilt at his manslaughter trial. That isn't a very happy way to start a marriage, and the fact that she was a superntural creature didn't improve matters. She gave birth to David and Roger wasn't even sure he was his son, although I guess he came to love him no matter what. Laura used Roger, and so shall Cassandra, his next wife.
Quentin preferred them shallow. Beth had such depth and loved him so much, despite his supernatural "handicap". Foolish man had an affair with her, then essentially dumped her when Amanda Harris, a two dimensional character from the paintbrush of C. D. Tate, came into his life. She was pretty, but vapid, and some might say the perfect match for the Quentin of that era, who for a long time was pretty vapid and superficial himself.
Love, Robin
