Angelique is probably my most favorite character from the series for the simple fact that she is so fun to analyze psychologically. For this topic, I agree with much of what Gothick has said thus far.
I think the common thread through all of the Angelique's we have seen (Parker's in the original series, Anthony's in 91, and now Green's in 2012) is that she is most simply a woman who is disgusted with her original station in life and seems determined to somehow move up through society. It just so happens that she decides to latch on to Barnabas in hopes that he will pull her out of the bowels of society enough to make a name for herself.
Certainly in the original series she was jealous of Baranbas' love for Josette, and I suspect, of Josette's life in general. She wanted to live the life of a wealthy woman and have all that life would bring to her. Much of her machinations during 1795 revolved around securing a man for herself that would allow her to live a better life. Wanting to conquer Barnabas was her primary goal and it seems easy for me, as a man (albeit a gay one) to say that Angelique thought she needed a man to better herself simply because I have gender bias and it is my perspective. But I don't think she necessarily was going after any rich man in town. She wanted Baranbas because she was enamored with him and if it helped our her overall life status that seemed as if it were a two for one deal.
We see this time and again throughout the series how Angelique is always going after Barnabas by way of Roger, Quentin, Julia, and anyone else she could manipulate in order to get to Barnabas. Much is made of, in all of DS' incarnations, Angelique's hell bent nature to make the Collins family pay for all that they have done to her. But no matter her actions, she isn't simply on a revenge kick against the family for no reason. It's highlighted in the OS more times than I can count that Angelique tries to blackmail Barnabas into loving her or being with her by threatening his family. It just never works out in her favor.
Despite the plot holes and numerous twists and turns, Parker's Angelique steadfastly remains as the best of the three incarnations of the witch simply because the show had the time to explore her character and really make her one of the most well rounded and full circle characters of the series as a whole. The 91 revival and the 2012 film simply did not have the time to devote to doing this and as a result Angelique seemed to turn out to be a caricature of herself and to seem utterly insane and without sound motivation for her actions. We see the common thread I spoke about above, especially in the 2012 movie with Angelique rising to power after turning the town against Barnabas in the 1790s. She becomes the wealthiest person in Collinsport and everyone and everything seemingly revolves around her in some way (which this Angelique seems to like because she seems very self centered and selfish. I don't think Parker's Angelique was quite as self-centered.)
I remember that one of my biggest qualms with the new film was that I kept getting the feeling that Angelique was happy with being the biggest fish in Collinsport because she had acquired fortune and was still close enough to the Collins family to keep an eye on them. However, I always imagined Angelique as being someone who had an insatiable appetite for power and always wanted to grow and be better than she was previously, which meant that she wouldn't have just been satisfied with conquering Collinsport, but would have wanted to expand beyond that realm throughout the rest of the world. Perhaps this is just my own imagination taking liberties with what we were shown. Nonetheless, I never got that feeling from watching the Angelique in the original series, but now that I think about it maybe that was because she never really gained complete and true control of the town Collinsport and because of that she always had something to go after and aim for--she never had time to rest on her laurels and count her dough.