Personal taxes are very reasonable in Switzerland. Despite the complex federalistic political structure, the Swiss tax system is very simple and the fiscal administration rather efficient.

Lump sum taxation
Foreigners with no activity (that is, retired) can choose to pay a lump sum annual tax, which is calculated on their rental payments (or the rental value of their house or apartment) with no relation to their real income or wealth.
More about lump sum taxation ...

Income tax
You pay taxes where you live, and these taxes are divided between the the federal government, the canton and the city (about a third at each level). There are wide variations in tax rates between cantons and even cities, and your overall tax bill will very much depend on where you live, even though it rarely exceeds 30%.

Wealth tax
Swiss cantons levy a small wealth tax of maximum 1% of your net assets (unless you qualify for the lump sum taxation). This is the oldest tax in the country and never assumes the retaliatory significance that it has in some countries.

Estate tax
Several cantons levy a small estate tax (i.e. inheritance tax) of about 7% between father and son, but this is being phased out by popular demand.

Capital gain tax
Switzerland does not apply capital gain taxes, except for professional equity and real estate traders.

Other pages of interest:

Lump sum taxation in Switzerland