Contrary to some of the reports that I read, this is not the worst movie ever made. Considering the cast and a reasonably promising premise, it was disappointing, but it wasn't that bad.
The concept (stolen fairly directly from Men in Black) is that there are those among us who are dead, but masquerading as the living. When discovered, their disguise falls away and they are revealed as monsters. Someone needs to find them and bring them in, so when some police/law enforcement officers die, they are given the option of staying on earth for a while and working for the Rest In Peace Department.
When Nick (Ryan Reynolds) is killed in the line of duty, he is given this choice and he opts to stay so he can be close to his widow (Stephanie Szostak.) The Proctor (Mary Louise Parker) pairs him with an old time law man, Roy (Jeff Bridges) and they stumble on a plan to build this ancient artifact that will reverse the flow of those who have died and flood the earth with the dead (I'm not certain if they stole this from The Avengers or Ghostbusters or simply melded the two together.) And, of course, we have a love story with echoes from Ghost. Originality is not a strong point in this movie.
My biggest complaint is that they billed this as an Action/Comedy; there was plenty of action, but not much humor. I don't remember laughing, or even really smiling, once. Jeff Bridges and Mary Louise Parker both chew the scenery, hamming it up to the nth degree, but while it is sometimes entertaining, it is rarely funny.
There are a couple of good chase scenes, but as a "buddy/cop" movie, it doesn't work. There is zero chemistry between Bridges and Reynolds; sometimes they seem to be in different movies. Kevin Bacon does bad very well, but that wasn't a surprise, we've seen it from him before. On the plus side, there are now new entries for the "Six Degrees of Kevin Bacon" game.
Rated PG 13, there is some profanity, a couple sexual innuendos and, for the most part, fairly cartoonish violence, but some of the monsters might be frightening for younger or more sensitive children.