Barnabas DID know what love was.....he wouldn't have been so desperate to find it, especially with every SYT or Josette-look-alike he came across if he didn't. And as already mentioned he loved all of his family, not just the 1795 branch but the present-day family as well, plus I also believe he had a great deal of affection for the 1840 Collins family. The 1897 family I kinda doubt for two reasons: [spoiler]they were a bunch of narrow-minded, opinionated stiffs (Judith and Edward fit this perfectly, a womanizing boozer (Quentin, although Barnabas and he did grow to be good friends by the time 1897 was over) or an immature clown (Carl, obviously Barnabas didn't have much affection for him, considering he winds up killing him! But I digress....)[/spoiler]
As far as the ladies went:
I think Barnabas truly loved Vicki.......even more so when he dropped the idea of turning her into the image of Josette. He and Vicki had great chemistry as friends, but the romantic chemistry just wasn't there. Vicki loved Barnabas but she wasn't IN love with him, that has a lot to do with how I feel about the situation.
Before the curse, Barnabas and Josette were adorable together, and had things worked out, I think they could have been very happy together had there been no Angelique. What happened with those two was a tragedy. I always believed Josette was and would always be the love of Barnabas' life since he spent so many years pining for her and wanting to recreate her with every woman he became interested in.
Angelique.....sorry but nothing is gonna convince me [spoiler]this woman, who tore Barnabas and Josette apart through black magic, who cursed him and killing most of his family with the curse as well, who tormented him throughout the centuries, was Barnabas' one and only true love. She did too much to him for me to buy the whole he-loved-her-but-didn't-know-it-til-it-was-too-late plot device the writers sloppily hatched out.[/spoiler]
Roxanne....never know what Barnabas saw in her. That's all I have to say about Ms. Drew.
Rachel and Maggie were nothing but Josette-clones (though I do believe he grew to care for Maggie outside her resemblance to Josette).
Lady Kitty Hampshire was [spoiler]supposed to be the actual reincarnation of Josette....unfortunately that too was doomed to failure. But one can't help but wonder if, had the Leviathans not intervened, Barnabas and Kitty could have had a happy life in the present-day. She would have had to go through the same adjustments to the 20th century that Barnabas had to make when he was released from his coffin in 1967.
[/spoiler]
I will shout it from the top of the lungs.....Barnabas should have turned his affections toward the one woman who had been totally devoted to him and totally self-sacrificing when it came to protecting and helping him.....Julia Hoffman! She loved him so much, and if he had only given her the chance, I think he would have felt more than friendly feelings towards her. She did so much for him, more than any of the younger girls he constantly fell for. I just wish he could have realized that on the show. I mean I know he cared for her, but feel he should have given her more of a chance for his love.