If you want to have the option to destroy GEO satellites at a moments notice, this would be the way to go. Adjust the orbit slightly and you've got a kinetic missile impacting a satellite moving in the opposite direction at a relative velocity of 14,000 miles per hour. You'd probably leave the entire GEO belt unusable for a few decades, but if the shit truly hits the fan on Earth, maybe you don't care.

Tons of telecommunications satellites in that orbit along with many other mission critical birds. Here's a list. https://www.n2yo.com/satellites/?c=10