Monitor vs tv. here is a monitor photo. it is a 24 inch monitor 1080p.
no tuner no speakers. I added speakers and a tv tuner.
next is a tv photo it is 32 inch 1080p. it has speakers and a tuner.
the 24 inch monitor allows close up viewing .
the 32 inch tv allows distance viewing. I have a 46 inch tv setup it is my preference .
A lot has to do with your eyes. IE if you have good close up vision you may like a monitor even a rMacbook since you will see it clearly. If your vision is good for distance you may like a 46 inch tv from around 9-12 feet. or a 32 inch from 3-5 feet.
If you like to watch a lot of movies a big screen may be what you want.
Most TVs are designed to be viewed from larger distances, like 5+ feet away. They tend to have fairly low resolution for their size because of that.
Desktop computer monitors usually have a higher resolution for their size and are made to be viewed from much closer.
TVs also often have a lot of image processing and scaling that goes on that doesn't work well for use as a computer display. Sometimes they will have a specific mode or option for computer use that disables some of those things.
If you want to use it primarily to watch video from a few feet away, a TV might be a good choice. If you want to use it while sitting at your desk most of the time you would probably be better off getting a real computer monitor.
Now monitor-tv's are appearing, which I think is a nice trade-off.
Monitors only do 60fps (unless you buy expensice NEC/Eizo ones), which stinks for video.
A TV is really capable at showing 24fps/50fps etc.
Now you see 27 inch monitors with built in media player and DVB-T tuner. Even the panels are upgraded from stinking TN to PLS or IPS panels.
I see a monitor as a must, and the TV hookup as a luxury / sometime use thing. I have a 27" iMac, so it's pretty rare I connect it to a TV / mirror it.
MY 17" MBP is the Mac that tends to get used with my Sony 46" 3D TV the most...I sometimes mirror my MBA to an older flat panel TV in the bedroom too. The image quality does depend a lot on the quality of the TV...The new Sony is LED and the image is sharp and clear...The best way to check is to compare a few in-store. the 27" ACD takes an awful lot of beating though, Other panels from Dell and LG also seem popular with many users here too.