"Taxation" is theft. It really is as simple as that. What else would you call it when someone takes your money (your possession) away from you by threat of force when you do not want to give it to them?
Do I have a right to my own life? What is "life" except the time you are alive? I have traded a significant portion of my life for money in order to trade the money for some other things I lack the knowledge, skill, or inclination to do personally. Does my life, expressed through my money, belong to me? If it doesn't, then taking it would be alright. However, if it does, then if someone takes it from me against my will, it doesn't matter to me whether it is a government agent or a mugger in a dark alley. Theft is theft.
Now, you may argue that the money is being spent on "good" things. OK. Maybe the mugger will use my money to feed his children, or will donate it all to a charity to feed widows and orphans. Perhaps he will even purchase a "gift" for me with part of the money; something I won't buy for myself. Does that excuse his actions? Of course not. Few people are stupid enough to argue that it does. Place the silly hat of "government" on the mugger's head, though, and many people fall for the lie.
What if I refuse to cooperate with the mugger? He will use greater force unless I am able to effectively fight him off. Just like government employees do. If you refuse to comply with those thieves, and keep refusing at each step of the "process", a point will be reached where they will kill you for your money. Either when they try to confiscate your property, or when they come to forcibly arrest you, if you fight back, you will be killed. What product or service is worth killing people over? Innocent people. People who only wish to keep that which belongs to them. Murder committed to support "authority" is not right.
Taxation is based on a fundamental lie: "government" doesn't even "need" your money to operate. They have access to the world's largest counterfeiting operation: The Federal Reserve Bank. Through this, and inflation, the government creates all the fiat "money" it could ever want, without stealing one cent from you through "taxation" (although the deception involved in fiat money, which leads to inflation, is still theft). Taxation is simply a way to take money away from you in order to cause you financial harm, cause you to alter your behavior to more statist-approved ways, and to keep tabs on you.
The things and programs that are financed with your stolen money, and that should be done, could be done cheaper and better by private companies or individuals competing in the market. "User fees" could be charged for some things. If those calling themselves "government" still want to be involved, let them end their monopoly and compete with voluntary services. Private roads could be maintained through tolls or paid for by the businesses they serve. Poor families could be helped by charities that do not take away their dignity like government "welfare" programs do. "National defense" would be better served by the militia than by the military pawns that are sacrificed for bogus "causes" in distant lands now.
Many, if not most, things "government" currently wastes your money on would not need to be replaced by anything in a free society. Stupid things like the DMV, BATFE, the Pentagon's "black budget", and Congressional salaries. These things add insult to theft.
Remember and think of these simple truths next time you think about paying a "tax".