Iceberg Ice Cubes
10,000 year old iceberg ice on scotch, I'm sure it would even be good in lemon-aid too. It is very dense. It would be, after tens of thousands of years of snow layers compiling on top of it. It lasts much longer than freezer ice(thank God, because on a hot day, and me with a sea kayaking dry suit on...it air-conditioned the inside of my cockpit for quite some time). And best of all, it still crackles, fizzles and pops, even when chopped up into small tiny glass size pieces for your drink. Cheers.