Migrain Medication

Does anyone know of a medication for migrains that is not addictive?

I take Nortriptylene (an anti-depressant) daily. I take Tylenol for "regular" headaches & Maxalt at the onset of migraine. Nortriptylene + better sleep habits has greatly reduced the frequency & severity of migraines for me during the past 6-7 months.

Imitrex is non-addictive, as well as relpax.