Chad got a new Samsung TV, but he's discovered that he can't stream YouTube with it from his desktop. Leo says that DIAL and DNLA is supported by Samsung. What may be happening is that the YouTube app on his Samsung TV may be in conflict with his mobile phone.
He'd need to get an Apple TV to do AirPlay with your iPhone. Chromecast is the cheapest way though. It's only $35. Check out this guide for sharing a desktop screen to the TV at allaboutchromecast.com.