I can sympathize with everyone who has gone through all of these prescriptions. I started with phenobarb in the late '70's and continued to try every new anticonvulsant as they came on the market. They all were frustrating and had terrible side effects at times (i.e. Topamax).
My neurologist prescribed Vimpat to me about six months ago. I have had great success with it. Since the drug just came on the market in (December'09?) it remains very expensive. My insurance covers some of it, but I am still paying about $175/month for the prescription. However, I find it to be well worth the money. I look at it like an investment for getting and keeping a job. The seizures have reduced about 75% and the symptoms of the seizures I continue to have are not nearly as extreme. I used to be exhausted after a seizure for about an hour and my mood would change for the remainder of the day. This does not happen any more.
I see that several people are quite far away from a neurologist in a metro area. I know this can be tough since I used to live about 60 miles from a large metro area that had a decent neurologist. My wife would have to take the day off and drive me back and forth, but we still found it to be well worth the trip.
Check Vimpat out - I have had no side effects to date.