Who said all movie series become worse with every installment? Lethal Weapon 4 is probably the best fourth movie in a series ever. I find it incredible that the magic is still there. The main characters still feed of each other and their friendship (both on set and off set) is clearly felt in every scene they have together. Mel Gibson has finally laid the ghost of his wife to rest and is as chipper as ever. He does this without seeming truly obnoxious (even though that is a part of his character). In fact he seems more likable in this film than he did in all the previous films. Danny Glover reprises his role from the previous movies and that is not a bad thing because the Murtaugh role is the best of his career. Rene Ruso returns in her part and although it has been cut down considerably its still a decent role. Joe Pesci is also back and this time around he gets to add some depth to the character (something that was missing in the previous film). Chris Rock is decent. He isn't much of an actor but he is pretty funny and fresh. His part also adds a little something to the all-round comedy of the film, but if you want to know what it is you will have to watch the movie yourself. Jet Li is the villain in this movie and while he is the weakest villain in the series acting wise, he is definitely the most menacing.
The action is still brilliant despite the fact that the actors are getting older. The story is decent for a fourth film and the overall execution is brilliant. I actually prefer this film to the second and third of the series because I find it to be more entertaining overall. It cuts down on the seriousness (even though its still there) and adds a lot to the comedy and this is a very good choice.
All in all an excellent film. Highly recommendable for all fans of action movies and the series in particular.