The greatest advantage of an UPS is for data protection for use with specific equipment that has recording or writing capability (DVD/CD recorder, PC, DVR, VCR, etc.) during an outage or brown-out.
It could also be useful for maintaining the 'cool down' cycle of a projector, by allowing you time to shut it down manually. I don't think the switching supplies in most electronics will be harmed by using a conventional UPS with a square wave for the short time required to shut down a system. Especially, compared with some of the ugly AC that exists at the outlet during brown-outs, etc.
Beyond that, many other solutions are out there that offer great surge protection. I like the Panamax method of removing power in the event of major AC over and under voltages. Afterall, no connection is the best protection.
ZeroSurge and Brickwall provide excellent surge protection and are designed to be used right at the wall, even before an UPS unit.
From there, pure sine wave UPS, combined with regulation are available. This is probably most useful if you want to ride out the storm, so to speak, and continue to enjoy your entertainment during an outage, etc.