For a TV
, use Avia.
It runs about $10 right now (used to be $50): http://www.amazon.com/gp/product/B00...SIN=B000X4NJNS
There are some other knock-offs out there, but Avia is "the" one to use.
For a computer monitor...
this can't be done in software alone.
You'll need/want to get a Spyder: http://www.amazon.com/gp/redirect.ht...reative=390957
Buy the best one you can afford.
The cheaper $72 version works well enough: Datacolor DC S3X100 Spyder 3 Express
The only other options is a quick and dirty method, involving a digital camera and standardized objects. For example, a Dr. Pepper bottle for magenta/red, and then something else to represent blues, greens and yellows. A clean piece of paper will help to calibrate whites. Your own eyes are generally good enough for detecting blacks.
Photograph the objects, then compare them to what you see on the camera's LCD and again on the monitor. Once again, compare against the printer(s). This takes a lot more guesswork than a Spyder, but at least it's not 100% blind, as you're trying to calibrate against realistic items.
Above all, remember these two things:
(1) You're calibrating objects against one another -- it's not an absolute measurement.**
(2) Some TVs/monitors are just really crappy and can never calibrate properly.
**You'll read a lot of fanboy-esque BS online, where this or that model/brand will give you a "perfect" or "true" quality, blah blah blah. It's all horsecrap. You have TVs/monitors that can be calibrated well, those that will partially calibrate (i.e., everything but reds look good), and those that can't really calibrate at all. Don't fall for those who give into brand loyalty or marketing BS -- which is common with Apple and Dell computer LCDs, Panasonic HDTVs, and to a lesser extent, Samsung and a few others. Just an FYI. What you'll read often comes across as if that specific model is perfect and flawless (and it's not, which is where "fanboy" comes in), and all other makes/models of TVs are like looking at a 1950s CRT.