Man I really, really wish Voyager had done a Borg origin story.
I imagine the Borg started as sort of Communism taken to an extreme. The original Borg probably formed a Collective for reasons similar to the formation of the Federation. To acquire knowledge, to set aside our differences. Then, like Futurama's Santa, it became something nobody intended it to be, and it calculated the best course of action was to absorb everything else in the universe.
I don't think the Queen ruined the Borg, at least not in First Contact. I think the ruination of the Borg is...well, Dark Frontier. It's the first episode that really weakened the Borg just to make it possible for them to stay part of the show.
You should read the Destiny novels. They detail the origins of the Collective and it's really more tragic than anything else.
It also sort of explained the concept of the Queen, and why she won't stay dead, convincingly enough.
But yeah, what ruined the Borg in the series is overexposure really. They show up once, they're scary powerful, threatening and the good guys were lucky to stay alive. They show up ten times, the good guys beating them off becomes just routine.