CaptainSauce, hands down, no competition there. He brings the quirkiness back to Sims 4 and his videos are different than what other simmers do. He has his own style and he is very respectful to his fans too. Like TeslaChick2 said, his voice doesn't make me cringe. I can listen to James from TheSimSupply and I appreciate his tutorials and building videos too but I think lately he has been... lets be polite and say "getting younger again". I kind of like CallMeKevin too, but his videos got a bit too violent for my taste. He has some potential though and some of his videos are hilarious!
So far I have found one (ONE!) female simmer who I can listen and that's English Simmer. Unfortunately her let's plays aren't my style though. Most let's plays aren't and that's probably because I'm in my forties and don't give a fruit of teenage/YA drama, every sim being fashion model, rich, bold and beautiful and friends with everyone or an emo and hated by everyone. Nothing wrong with those let's plays, but it doesn't entertain me anymore. I enjoy Sims videos that bring something new and original to the table. Video's that encourage me to try different things in game. It's just very difficult to find them.
If I'm looking for information about what game packs to buy, I go for LGR aka Lazy Game Reviews. I know some people think he hates the Sims but I don't think so. I can see where he is coming from and I appreciate his honest reviews. His reviews have not made me stop buying Sims content, quite the contrary. When I watch his review I know what I'm getting and I feel more confident on buying new packs than I did before.