well i have grown a lot of strains but i would have to say the ones i disliked most are usualy dead before thay get too far into flower if they are not up to par or important, but i have grown plenty of bag seed that just plain sucked. bu tan actual strain. hmmm... i would have to say ICE its too airy and its strong and good but it never taste right and i could never get it dense enough for my liking, could have been the cut i got, but i trashed it after i was unsuccessful with it 2x in a row.