Let’s see some pros and cons.

TV Sets

Pros

• TVs come in large sizes. It is relatively cheap to get a 32″-55″ sized TV set.
• Almost all TVs have HDMI inputs, so it is easy to connect them to a Xandabox (or any other type of player).
• TVs also have speakers, so you can also use audio.

Cons

• TVs (up to 24″) are generally more expensive than computer monitors.
• TVs cannot be powered off simply by deactivating the display port (HDMI/VGA/DVI port).
• Some TVs (e.g. LG) cannot be powered off at all, even via HDMI-CEC. So, you cannot power them off easily. See the HDMI-CEC vendor compatibility matrix.
• TVs have remotes. In case you want to leave them unattended, you must deactivate the remote receiver, or a prankster might use a remote to fool around.

Computer Monitors

Pros

• Computer monitors are cheap, cheaper than TV sets, especially below the 24″ size range.
• Most units tend to be lighter than TV sets.
• There are no remotes, so it is not easy for someone to play around with the monitor.
• All computer monitors support power on/off.
  

Cons

• Computer monitors generally do not have speakers.
• Computer monitors larger than 24″ are usually more expensive than TV sets. And more rare. It is difficult to find a computer monitor larger than 32″, and if you do, it is insanely expensive.
• Not all computer monitors have HDMI inputs. So, you might need a HDMI-to-DVI adapter to connect a Xandabox to them. (VGA-only monitors are now rare, so let’s skip them)

Conclusion

If you have a new installation, then we suggest:

• Computer monitors, if you need up to 24″ in size (with or without speakers, depending on your needs)
• TV sets, if you need panels larger than 24″, but make sure that the vendors supports Power On/Off via HDMI-CEC. See the HDMI-CEC vendor compatibility matrix.