I have seen a lot of commercials for clinical strength deodorants lately. Those might be something to look into.
Another thing to try is a more natural approach.
The Crystal Body Deodorant Stick is a decent product, but it can be difficult to find depending on where you shop. It's a bit on the expensive side, but I find that it lasts a very long time, so it actually works out being less expensive in the end. I used this product alone for a little while, but it didn't work all that great for me. So I kept using that product, but then I would put either
Crystal Crystal Roll-On Body Deodorant,
Kiss My Face Liquid Rock Deodorant, Peaceful Patchouli, or
Tom's of Maine Natural Deodorizing Body Spray, Calendula on over it. Now those three are also sort of expensive. But I found by using the solid one, then a liquid one, I get the protection that I need. The Kiss My Face stuff smells good and rather strong, so it's almost like having a deodorant and a light perfume on. I use them up a lot faster than the solid one, but they leave no white residue or anything, so they're great for sleeveless outfits.
And if you can't get any of this over the counter stuff to work for you, talk to a doctor about it. He might be able to tell you some thing you can change (such as diet), recommend other deodorants, give you prescription deodorant, etc.