The Value of Forstner Bits
Does every woodworker need a complete set of Forstner bits? In truth, many other less expensive bits - like brad point bits - will do a nice job in many situations. Keep in mind, though, that Forstner bits have a few qualities that make them indispensable in certain situations. You may be able to get by without a set of Forstner bits, but if you stick with woodworking for a few years, you'll probably end up with at least part of one - purchased one at a time out of sheer necessity. When you weigh the cost of individual bits against the much more friendly price per bit afforded by a complete set, the set starts to look like a bargain.
What's so special about Forstner bits?
Unlike the standard twist bit, Forstner bits are optimized for woodworking applications and cut exceptionally precise, clean-edged holes in wood. Because they're designed to produce a minimum amount of tear-out when exiting the material, Forstner bits are the best bit for drilling through holes. Forstner bits drill a flat-bottomed hole, making them a necessary tool for many hardware installations where a precise depth of mortise is required. Forstner bits are guided by the wide outside rim of the bit, unlike most drill bits, which are guided by the tip. Because of that, they can be used along with a drill press to drill angled holes, holes that partially overlap, and holes on the edge of the material.
The 7-Piece Forstner Bit Set is a good basic set and contains the most commonly used bits from 1/4" to 1". The 16-Piece Forstner Bit Set gives you the advantage of having a few of the more costly larger sized bits up to 2-1/8'.
Rockler has a 22-Piece Set of Forstner bits. The set is precision machined and polished, comes in a sturdy wooden case, and in all likelihood contains every Forstner bit you'll ever need.