My can opener.
This one just breaks the seal of the can and leaves a smooth edge. My friend bought this for me for my birthday a few years ago...for a craft project actually. I use it often and I love it!
Truth be told, I'd still be using my old can opener that leaves the rigid, sharp edge if she hadn't been so kind to give this one to me, it sure is nice to have good friends!! (Thanks, by the way...you know who you are!!)