The only Let's Play that will ever be worth a damn is a Let's Play that's funny as hell. Since most games that are funny as hell to watch involve fucking with the player, it 100% defeats the purpose to research it and watch someone else's let's play about it.
99% of Let's Players aren't funny unscripted, anyway.
When I want to try a game, I look for a more "serious" letsplay/commentary on it. That way I can do other things while getting most of what I want out of the game. When I look for entertainment while I eat, sew or for my evening routine, I watch PewDiePie, Azuritereaction or Cry. There's a situation for both types
I can't imagine why I'd be watching someone play LoZ, but often if a game is horror or story based, I find it more interesting to see realistic reactions. But that being said, I haven't watched a Let's Play in many years anyways.