Frostiest...there's so many different kinds of frosty. There's the slick-wet look of a nice sativa, the ice queen look of a potent afghani, and the resin fuzz profile common to the chem family. In no particular order, some of my frostiest strains from seed have been Killing Fields F3 (Sannie), Tranquil Elephantizer: Remix (bodhi), Goji OG (bodhi), RKU F2 (my f2 of Bodhi's strain), LA Chocolat (DNA Genetics), Anesthesia (whazzup/breeder's choice), White Dawg (top dawg), and Dream Beaver (bodhi). Some of the frostier clones have been the super amazing CO Durban Poison cut (squat christmas tree structure w/insanely drippy chunky buds), the Blue Dream cut, Fort Collins Cough, and the Colorado Flo cut.
Goji OG
Anesthesia
LA Chocolat
There's a few.