Really for a lets play the game that you choose doesn't matter much. The most important features are the content and theme of the actual lets play, for example two people may do a lets play of Terraria, one goes about fighting in caves and exploring, with humours voice over. The other person does a lets play of them staying in their hut with no actual vocal or sound, doing nothing except crafting. These are two extremes but the first one will receive more views.
Choose a game you are comfortable with and then think about what you want to do in the actual episodes (e.g. Build a house and go exploring, Fight all the time, etc) even if you voice sounds bad try doing at least one episode with vocals to test out whether with vocals the lets play will be a better experience to the viewer.
Even through the game does not matter as much as what you do, choose a game with an open game play where the player chooses what to do, it will make the Let's Play more unique to you and also allows you to vary your activities to keep viewer interest.