Loading Ready Run doesn't always play through a game, as they make a lot of stuff, but they do have a thing called Play It Forward where they do do that. There's several competed games in there, I think. They're all streams first so not very edited though.
Not quite what you are looking for, but tehsnakerer is my favorite YouTuber who plays through video games. Not quite let's plays, though, more extensive critiques
I used to watch ClementJ's Mega Man X and Zero LPs.
RTGame
He was known as the Drift King back in college, don't ya know.
I started Game Grumps over a decade ago, and still enjoy most videos to one degree or another. Most games they don't finish, but they always have at least one game that they are working through
With as much controversy that channel has had, I'd steer clear
Definitely chuggaaconroy
He's playing through Mario & Luigi: Bowser Inside Story right now! I'm really enjoying it
CohhCarnage
ScaryGamesSquad (SGS) videos on JesseCox.
Sips
Thru games, as in from start to finish? Macopopips...Mapocolups...
this guy...
I love Mapo! He’s always super thorough with his playthroughs and finds so many hidden things it’s impressive.
I also recommend ChristopherOdd as well for more strategy based games.
Sub for any gaming related content!
Rules: