The LG 4K Ultra HD Smart TV with webOS 2.0 (2015) is one of the best deals out there to get an easy to use TV with 4K and Smart TV functionality.
If you want even more fun and already a heavy user of iTunes or really just love the Apple user experience, you can purchase the Apple TV (2015) which is also quite affordable. Most Apple products are sold at a premium vs other similar products in the market but the Apple TV pricing is actually similar to other products from Amazon and Roku.
Even though the Apple TV (2015) doesn't yet support 4K, it works well on any HDMI port of the LG 4K Smart TV. You can immediately enjoy your iTunes library or download applications like YouTube to enjoy a greater variety of content.
Because the Apple TV doesn't support 4K, all of your video will show up as 1080p on the LG 4K Smart TV.