BloodRayne: Betrayal

Chapter 3 is a good idea. I'm currently trying the following within that chapter:
After the fight with the blade armed vampires show just after the lights come on, you'll see a hive for mosquitos. Leave it alone and continue right toward the first moving spike obstacle. If you stand just to the right of it, the mosquitos will endlessly spawn. Their flight pattern/AI has them run into the spikes unknowingly and explode. I'm just not sure if they count as enemies. I'll find out shortly. You can get about 10-15 per minute if the patterns line up right and you can eat them as snacks as your health gets low.

The other place that's probably good for faming this are the levels which are autoscroll vertically, especially Chapter 14.

I can't edit my previous comment, but I can confirm that both methods work. I farmed according to my first method (derived from your suggestion regarding chapter 3) for about 25-30 minutes before giving up and wondering if any of it counted.

I then moved to chapter 14 and used the saws/spikes to kill anything i could, throwing the rest off the edge of the rising platform into the blood. After about 5 or so runs (netting 6-20 kills against environment in a couple of minutes), I had it pop.

I was playing on PS3 however, so the site won't let me write a guide, since I don't have the 360 achievement. I can vouch both my suggestions worked in the end though. Thanks again for the suggestion; without you, I wouldn't have even known a good place to start right off. :)