I would recommend a simple plugin box such as the Roku or Apple TV. Both will allow you to access content from providers such as Hulu and Netflix and provide options for streaming content to them from your PC or phone.
An HTPC (Home Theater PC) isn't a bad solution if you want to keep a large media library connected to your TV. But, an HTPC will easily cost at least 5 - 10 times than what a Roku or similar device will set you back ($50 - $100).