Chain link is the most ubiquitous fence type, due to its low cost and simplicity. The other advantage is that you can see through it, so if you have features in your yard that you'd like to showcase, such as a flower bed or fountain, or if you would like to be able to see through the fence into a natural area beyond, a chain link fence is a good option. As far as functionality, a chain link fences provides a good level of security for your family. It usually lasts about thirty years, and takes little to no maintenance.
Wood is a very popular, from the classic picket fence to more modern designs. Wood fence installation costs a bit more than chain link does, but these fences can provide more privacy, since you can choose a design that provides a solid wall around your yard. The average life of a wood fence is about twenty years, given annual sealing or painting every few years.
Vinyl fencing has become a popular alternative in recent years because it provides the looks of wood or wrought iron fences, but is easier. Vinyl fence installation costs a bit more than chain link or wood, but the advantage is its long lifetime of service, and the fact that it takes almost no maintenance beyond an occasional washing, depending on the design you choose.
The wrought iron fence is a classic look that, for many, is impossible to duplicate. Wrought iron fencing is also stronger and longer-lasting than most any other type. It provides a good level of security, if protection is what you're looking for. It does, however, require some upkeep—it needs to be re-painted every fifteen years. Also, it doesn't provide quite as much privacy as others. Another consideration is that wrought iron fence installation is more expensive than most any other type.
A final word on fence installation: whichever type you choose, fence installation is a job that, with the right equipment, can be done by the skilled do-it-yourselfer. But if you've got a hilly yard, or varied landscape, you'll need to do some planning. It is also possible, if you're looking to save money but still get a quality job, to do some of the work yourself, and hire a fence installation professional to finish it off.