I am working on something, and want it to have a screen.
I was thinking of using TFT LCDs, but have now thought of interfacing my Vizio TV with an Arduino (Mega)! The code (library) seems simple. But I would like to know just HOW to wire an Arduino to the TV. I know I'm supposed to cut and splice an RCA plug and all that jazz, but the instructions I found were vague. So how exactly do I wire the Arduino to my TV? Please any help is appreciated greatly! 
The best information I have seen is from Tronixstuff but when you get through all that jazz you may sensibly conclude that maybe using an LCD was a pretty good idea after all. If you want to get serious about using a TV, you might consider using a Raspberry Pi instead. It has RCA and, yes, HDMI output, so you just plug your TV in, and you are off to the races.
WesleyRTech:
I know I'm supposed to cut and splice an RCA plug and all that jazz, but the instructions I found were vague.
Link please.
It all depends on what video inputs your TV has.
You will not have very much processing power left after generating a TV signal with a Mega, and the resolution is going to be very poor.