I was promoted to Diamond for 1's just 2 days ago. I couldn't have improved as much as I did in these shorts months without a certain friend. Just 5-6 months ago, I started SCII in Silver. This friend wanted to be a caster soon after I started playing, so I started sending him my replays. I learned a lot from his commentary; he isn't afraid of being brutal in his feedback even to friends.
Here's the link to his channel: http://www.youtube.com/user/Droopytown?feature=g-all-u
I find his casts to be very entertaining as well. He takes on different personas (sometimes in the same cast) while still being on top of everything. The thing is, he's against self promotion. Consequently, he has only 26 subscribers on his channel after all these months and over 50 casts. I'd really like to put his name out there in return for what he's done for me. He hasn't asked me to do this for him. I just think he deserves it.
If you have a bit of time and like watching casts, I really do hope you'll take the time to check out his YouTube channel. He's a Diamond-level player as well. He's up for casting anyone's games. His email is included in all of his casts. Please subscribe if enjoy his casts. I feel like he really needs the motivation. He was very happy doing these casts at first, but when so few people subscribed after all these months, his attitude changed. For some reason, he just doesn't understand that getting your name out there is 75% of becoming a popular caster. Content is the other 25%.
Here's a very entertaining game he casted recently between a Master-level friend and the well-known MaximusBlack: http://www.youtube.com/watch?v=A4zJQpdePpI&list=UUpO6j_DMUFEKLeDPZ8E-jLA&index=4&feature=plcp
Thanks a ton for your time, especially if you read the whole post.