Canned food.

[phalanx]

And can openers, if it’s an old one those lids can cut the crap out of you. They get dull and don't completely cut very good i guess. One got me trying pry it off with a butter knife. I saw that some do a roll over cut now, so we bought one of those.
Works very well.

[Bob Riebe]

They vary, I have one at one house that is at least 50 years old, lost the lid magnet by not paying attention, attached with a metal clip, but I really do not need one.

Up where I am now have gone through four of the new improved ones in thirty some years; I have a manual one that cut on the outside but rarely use it.
The newest, was made using the lid magnet is attached with plastic broke of within a months of use.

Some cans though it seems , usually from rough handling by stockers, cut poorly.
I used to be able to cut it till it just poke up a littl still attached but lost patience to do that.

The small manual, often with advertising, ones that have can piercer and bottle opener are the best but wear out after forty years or so and the new ones are crap.

[Ranger99]

After using a side cutting opener, I
don't use anything else for home use.
I still have a couple of scout/camping
knives with the old traditional eagle beak
can opener, and a couple of the military
version. I don't think many younger people
would know how to use a traditional manual
can opener, especially a P38/P51 stamped
steel gizmo. Most all canned goods have
a pull tab these days, and people that actually
know how to cook are fewer

[ironglow]

I haven't thought much about my can opener recently.  It must be 10 years old anyway. it is an upright with the magnet lid holder.
  I have not been pleased with any of the power models we bought over the years..a bit too flimsy.

[phalanx]

I think the one we had was about 20 years old. The cutting wheel was dull and worn out so it would skip around the top. Wife bought this new one from a cooking show. Yeah, she watches those boring things lol. Exercise shows also, yoga and things like that 

[ironglow]

  I have found the dagger type cutting edge to work better and longer for me, than the cutter wheel type.