The hot thing in scanners right now is digital trunking. Most public-safety services use this approach, without scrambling or encryption. Analog scanners are useless, but the new generation of scanners include direct support for digital trunking.
I recently bought a Uniden/Bearcat BCD 396T, which totally restored my ability to listen to common public-safety traffic where I live.
Some more sensitive government agencies use encryption on top of digital trunking, but there’s no strong survival-oriented motivation to listen to their transmissions. Unless you’re trying to survive an FBI manhunt, I suppose. In an emergency, being able to monitor fire and police agencies should be enough for most people, and these new scanners can do that in most areas. Regards, – PNG