I love my Black & Decker Spacemaker Under the Counter electric can opener that I have had for ages but when I read about the ones available on Amazon today the reviews are not kind.

I get the feeling that modern B&D Spacemaker under cupboard can openers are not like the ones from the "good old days" ... sort of like modern Singer sewing machines are not like our old beauties. Maybe you can find a vintage new in the box Black & Decker under cabinet model on eBay ...

I have a Hamilton Beach opener that I like. I put the can lid under the blade and then push down on the lever on the top and it holds the can in place for me. Now i usually hold it anyway but one doesn't have to.
I once had to think quickly when in sales because i was asked for a can opener for someone with one hand. I'm not sure what they ended up buying but that made me think more of the needs people have out there.
Hope you find one that works well for you.