You pretty much need something other then a PC due to DRM. For example google movies will not give you 5.1 audio or 1080p on a PC but will on the Chromecast. An xbox one S will play most things, but not google content. Functionality may be restricted by country.

DVDs are only 480p, you really need something higher quality on a new TV. I have noticed that HBO streaming looks better to me then cable.