I always use ibuprofen. I get pretty bad cramps around my 'time', and I find that it helps a lot. Motrin contains ibuprofen. Tylenol is also a pretty good painkiller, too. Both work well for headaches and cramps, I've found.
If you don't take painkillers, than there are some other options, too. Heat is very good for cramps-- a heating pad or a warm bath does wonders. When you are on your period, (and you've probably heard this a million times), try to stay away from salty foods. It sounds crazy, but not eating them really does help. :)
You can also get homeopathic remedies which are of course natural they take a couple of months to start working but I know from experience they reduce the problem not necessarily completely but to a point you can live with. So ask a Homeopath.
You can take ibuprofen or midol, but I dont like to because i heard it makes your period last longer. I just heat up one of those heating pad things (technical term for it) & just lay it across your lower stomach, or eat some bananas & chocolate. Thats what works for me.
Ahhh, I think people have done it already. XD But Ibuprofen is certainly the best medication for period pain; only have to wait a couple minutes and it's gone, just like that.
Though a really nice touch is to put a warm to hot damp washcloth on your lower stomach, above the lady parts. It can really help soothe. And I heard chocolate can help too. XD
Stay away from caffeine! It supposedly makes you feel worse.