TrueType fonts can be scaled to any size and are clear and readable in all sizes. They can be sent to any printer or other output device that is supported by Windows. OpenType fonts are related to TrueType fonts, but they incorporate a greater extension of the basic character set, including small capitalization, old-style numerals, and more detailed shapes, such as glyphs and ligatures. OpenType fonts can also be scaled to any size, are clear and readable in all sizes, and can be sent to any printer or other output device that is supported by Windows.
PostScript fonts are smooth, detailed, and of high quality. They are often used for printing, especially professional-quality printing, such as books or magazines.
It depends. If you want a font that prints well and is easy to read on the screen, then consider using a TrueType font. If you need a large character set for language coverage and fine typography, then you might want to use an OpenType font.
If you need to print professional-quality print publications, such as glossy magazines or commercial printing, PostScript is a good choice. For more information, see Fonts: frequently asked questions.