Well, UPS and modems are probably a different story. You should have a UPS to protect your hardware, though if it is not at least line-interactive it won't do much more than a surge protector, hardware-safety wise (data is another story).
We mostly own APCs, though all of our new purchases have been Tripp Lite.
Most modem frying comes from 'phone lines that are too hot. The 'phone company will do this because telephones are more resistant to hot power and it tends to result in less audio quality complaints. They will also vary the voltage at will, again because for an analog voice line there is no issue.
If your 'phone company offers "data certification" for the line and it is not prohibitive in cost, this will help. A lot. At least, it does for Verizon.
You should also get something like this:
That specific product is not exactly what you want, we use PTEL2 & PTEL4s, but they don't look like that so I must have ended up in the APC subcategory - but the protection idea is the right one.
Yes, I even use them in my home - for PVRs, phones, everything.