If you live in an area where the power is never 100% stable, as I do in South Florida, surge protectors are a way of life. We lose power at least once or twice a month. I use wall mount surge protectors in every outlet (6 plug flat mount - plugs into both outlets and screws into the outlet replacing the plastic cover. These are 1080 joules. The home theater has a 2100 joule Monster I got cheap, and the main computer is on a 4500 joule control box) I also use UPS boxes for all electronics - computers, Audio, TV, size varying with device.
As someone said before, its the brownouts that hurt the electronics. However we have had a number of incidents where a surge follows the brownouts. After replacing one TV, and finding a melted surge protector on the wall that protected a computer, the surge protectors are cheap insurance.