CDs! I'm forever shredding my nails trying to get the blasted security tape off the top.

Also, the hard packaging you mention is also used on children's toys and toothbrushes -- two items whose wrapping I find particularly frustrating to penetrate.

This is one reason I do most of my shopping at charity shops/thrift stores, which tends to make my CD collection quite eclectic and stocks my son's toy chest with truly fascinating oddments (though I do draw the line well short of buying my toothbrushes second-hand).

C