As stated, the Mac Mini can be a very good option for playback to a 720p or 1080p HDTV. A few things to consider would include – types of movie media to play and, what player use. What I suggest is that if you have a Mac Mini 2.26 running CPU or greater, explore the use of PLEX or XBMC. They are extremely flexible home theater front ends on the Mac. There is a small learning curve but they are both FREE and meant to be front ends for your Mac_to_HDTV. The Mac Mini can provide two types of audio output – digital and analogue. The former providing the ability to do 5.1 surround and the latter stereo.

If you have DVDs and Blu Ray that you wish to archive to a hard drive, enlist the use of MakeMKV. When this software scans your purchased DVD or Blu Ray, it will give you options on what you want to do/save. In most cases, it would be the main movie, audio (5.1) and as needed, subtitles. It is a FREE software for now as it remains long term in beta. The above software can play these types of mkv files. There are of course other tools to convert into either smaller files (Handbrake comes to mind) or more standard formats such as .mt2s or .ts files (more like the original blu ray).

if you plan to use 5.1 surround, consider running the digital out of your Mac Mini into a receiver capable of toslink input and surround output. Both XBMC and PLEX have avid users who constantly add advice and answer questions in their respective site forums.

Last – if you like gadgets and to get more bang out of your system, there are ways to merge* the digital/analogue audio out with the dvi/displayport video and end up with HDMI going to your HDTV. What this does is give you one cable to your TV and ideally beyond less clutter, a nice way to to use the audio out passthru of your TV like your other equipment.