Remember that song "People who need people..."? I tend to care about the characters whose purpose involved watching out for others, and still entertaining us daily:
Vicki - because if she didn't care about that motley Collinwood crew enough to face ghosts, witches, vampires, Matthew Morgan, time travel, co-stars with hair obsession, bleeder valves, etc., we wouldn't be here today.
Barnabas - because he wanted so much to protect the ones he loved, yet anyone he loved ended up.... well... enjoy the series and carry a box of tissues.
Julia - because she loved the humanity of Barnabas, despite his inhuman tendencies.
Chris - because he loved his orphaned kid sister enough to stick around and face the light of a silvery moon, and live in a musty cottage Mrs. Johnson was too scared to dust or vacuum..