Personally I’ve always found video feedback to be among the most valuable. You can see how different people play and react in real time to your game, and a lot of users at /r/playmygame agree. In an effort to make it easier to get in contact with people willing to do so, I have made a resource to gather let’s players who are interested in indie games.
If you use this, please keep in mind these people are willing to take their time to play *your* game, be respectful and reasonable and don’t expect every person to be willing to play your game. Obviously, higher quality games will likely get more channels eager to play!