Jericho starts off with a bang--literally--when a nuclear bomb goes off in the middle of the US--probably Denver. The explosion is witnessed by the residents of Jericho, Kansas, who then have to deal with the aftermath of what proves to be a nationwide attack that has leveled several cities and rendered US civilization as we know it a thing of the past.
Just before the explosion, Jake Green (Skeet Ulrich--Into the West
The first few episodes, dealing primarily with the aftermath of the bombings, were the most interesting to me, although also the most disturbing and the most likely to inspire nasty apocalyptic dreams (although that could have been the hot buttered rum). In later episodes, the show seems to be devolving into a soap opera, though the specter of the nuclear bombs and the decline of civilization does rear its ugly head from time to time. The cast of characters is a mix of tepid and genuinely interesting. Jake is that blend of good guy and badass that I usually enjoy far too much for my own good, while his father is a bit too convinced of his complete rightness to hold my attention. (Plus there was that whole flu thing...) Hawkins (Lennie James --Snatch
I think the biggest flaw of Jericho is probably also the thing that makes it tolerable to watch. Based on what I've read on the subject, the aftermath of this kind of attack would be far worse than what's depicted here. I could see HBO or Showtime doing a much more realistic treatment of a nuclear apocalypse, but I think such realism would be so grim as to be unwatchable. Even Jericho, with its watered down, prettified version, seems to carry the underlying message that, when chips are down and we all need each other, people will still pretty much act like assholes. So the showrunners have undercut the widespread effects of things like nuclear fallout and radiation poisoning, put in elements of typical serial dramas, and have ended up with a show with fairly wide appeal. On the other hand, they've made it look like a substantial part of the nation could survive multiple nuclear attacks, which seems unlikely to me.
Overall, Jericho is an entertaining show, if not one that will capture my all-abiding love. And it'll have to go to the DVR for timeshifting, since it's on opposite Bones, and even Skeet Ulrich's good guy/badass cannot outrank David Boreanaz's exceedingly wide shoulders.