Any LP that doesn't involve the player talking, repeating whatever the characters on the game are saying, cursing, yelling, etc. is unique to me.
What I would like for LP's to do is talk only when necessary, talk about what certain sections or levels or characters mean to you, explain how to find certain secrets or hidden weapons or levels. In other words, be informative.
But then again, most act like teenage assholes that think they are funny because that's what gets the views.
The Jurassic Park Trespasser and Yakuza Kenzan LPs may be up your alley, if you haven't seen them both already. Focus is totally on explanation and there's almost no humour. Superman 64 is naturally more humorous because it's making fun of a bad game, but it's mostly in that same informative style.
All already posted in the thread.