Sounds like you give your can openers a good workout. If you don't mind a huge contraption hanging off the end of your counter, you might give an Alegacy Standard Restaurant Can Opener a try. It has a metal base plate that mounts to your counter with a bracket that extends out the side. The business end is on a long (12"?) metal bar so you have no problems opening #10 cans. The hand crank is heavy duty and makes quick work of any size can. It is also rebuildable.

These are staple items in restaurant kitchens. I remember using them in my Dad's restaurant for over 20 years and I don't think it ever needed replacement or repairs.

Not bad price either, around $50-70 in a restaurant supply store. The downside is it hangs over the side of the cabinet.