I've had some luck with Imitrex, but I have to take it as soon as I feel a migraine coming on or it's useless. I usually cut a 100 mg in quarters and take it with 2-3 Ibuprofens. When I got really bad ones, I would add in a Lortab too. My doctor referred to it as my migraine cocktail.
I've tried Relpax and Topamax too. I found more relief w/ Topamax, and less side effects.
I found that my migraines were allergy related. I started taking allergy shots last summer, and have found that my headaches have nearly disappeared. I used to get at least three a month, and now I've gotten one in the last four months. The shots have been a lifesaver to me!
Good luck, I know how frustrating and debilitating migraines can be.