So I'm a fan of ice cubes or frozen bottles made from seltzer/soda water/club soda. It's cloudy and snowy without even trying, crunchy and easy on the teeth...the best of many worlds. I've been experimenting with a few and here is what I've found.
Best frozen seltzer:
CANADA DRY
It makes a very flaky soft soda ice. It melts in your mouth and gives you a reason for living.
Most dangerous seltzer:
TRADER JOE'S
While this makes a very decent soda ice, when you crack it, it pops something fierce. Pieces of flying ice has often gotten near my eye. Be careful freezing this brand.
Most Flavorful:
A tie! TRADER JOE and POLAR ICE
Trader Joe's seltzer water, despite its dangers, has really strong flavoring, overwhelming at times but good.
Polar Ice has the most interesting flavors. My favorite? Granny Smith Apple...it's extremely refreshing when frozen.
Most boring:
VINTAGE
Great drinking seltzer water, but when frozen it is just kind of blah. Also it usually freezes too hard so it's not as soft on your teeth as the other kinds.
The researching continues. Let me know what I've missed.