Like the two previous posters, I strongly recommend the EP-2050. In addition to protecting against surges it lowers the noise floor by removing hash and other distortion coming in on the lines as well as the stuff placed on your house lines by the various and many in-house devices that are plugged in. In addition, I use several parallel filters and passive conditioners and have found Alan Maher's circuit breaker filters quite effective.
If I were limited to a single device, it would be the EP-2050.
If I were limited to a single device, it would be the EP-2050.