There are generally two classifications of taxes
progressive, in which those with higher incomes bear the brunt of the burden (pay a greater percentage of their income), and
regressive, in which the reverse occurs.
The American system of income tax is an obvious example of a progressive tax. Middle class people pay a fair percentage of their income in income taxes, and the poor don't pay any income tax at all, in fact, they may actually get money from those who do pay them through the Earned Income Tax Credit. The wealthy can frequently structure earnings in a way to minimize the amount they pay in income tax.
Sales taxes would be an example of a regressive tax. People who save don't pay sales taxes, but lower income people have to spend higher percentages of their income to live day to day. For this reason, a sales tax is a much greater burden for someone making $10,000 yearly than one making $100,000.
Corporate taxes are another regressive tax. Corporations sell goods. Any taxes levied on them is passed on to consumers. Since the poor consume far more than they save, they pay a good chunk of their funds in taxes passed along to them in this way.
Some taxes pass wealth from one demographic to another. Social security is one example. This program is effectively a transfer of money from people who die young to those who live long (since the benefits only pay until death and are not inheritable). In America, I have frequently seen this phenomenum presented racially: Social security is effectively a tax on black men (who work but die young on average) to benefit white women (who live much longer).
Due to the inherent inefficiencies of government, we can generally be sure that our tax dollars are being spent as irresponsibly as one reasonably could without being arrested or sickened by one's own since of decency.
No one has implemented any reasonable alternatives to taxes in any country I'm aware of, and the constant struggle is between lowering taxes and reducing government functionality, or raising taxes and increasing government functionality.