Excedrin for Migraines is great for my migraines, however - the interactions of the aspirin and ace and caffeine all mixed together can leave you with a residual headache the next day - and so you will take more, which will damper the headache, until your dose runs off... then you'll take more.
Don't get caught in this - if you're experiencing headaches after taking Excedrin, switch to a different pill.
If you get tylenol with codeine (Tylenol 1's), that can help as well.
These are the two I always use, if I ever have to.