but for me,the Shivans are like a mix of the Borg and the Cylons.
or maybe I need to stop watching BattleStar Gallactica and Star Trek for a while

I wouldn't sweat it. I've heard someone say they made a connection or similarities of the Shivans to the Reapers from the Mass Effect series.

The Reapers from Mass Effect are a carbon copy of the Shivans. This is obvious if you have played Mass Effect 1 shortly after Freespace :)

They're clearly The Shadows from Babylon 5. Which in turn are a pastiche of the forces of Mordor from LOTR. :P

lol I think it's clear that most space opera is heavily derivative.

While I agree space opera can be derivative (like any fiction), I think the shivans and reapers both are just copies of Babylon 5's Shadows. The religious tones, insect bodies and countless cycles of extinction make it feel very similar.

with a healthy dose of Saberhagen's Beserkers thrown in. :)

Only problem with that theory is that the Shadows had a very set philosophy -strength through conflict- which is polar opposite that of the Vorlons.

The Shivans have no such philosophy or motives, and it's been hinted at by official sources that the Shivans are a constructed race, rather than an evolutionary one like the Shadows.

Well it is not clear if the targets is just because of technological progression or technological progression and aggression. The Blue Planet mod team for instance made it so that the Shivans are almost attracted to conflict amongst other species which given the Ancient and Bosch videos is not an unreasonable theory. The exact reason has not yet been revealed in that series though there seems to be a larger goal in mind.

I always thought they were attracted to subspace activity. Like moths to a flame.

The Shadows didn't try and rid the galaxy of technologically advanced races -they tried to force evolution through conflict, thus assuring that only the strongest survived.

I want to see someone put a budong from farscape into their game.