Mr. Nice Guy is not the greatest Jackie Chan movie, but it's not the worst either. There are moments that are as great as in any other Jackie Chan film, but there are also some negative moments because some aspects involving the action sequences are different from his other movies.
The plot is minimal: Set in Australia, Jackie (Chan) is a chef showing off his culinary prowess on national television. He literally runs into a TV reporter Diane (Gabrielle Fitzpatrick), who is trying to evade two sets of mobsters after capturing a fouled drug deal between them on videotape. The videotape is what everyone is after and Jackie is the only one who can sort the entire mess.
The movie contains great action sequences, but the ending, which has little to do with martial arts skills and is a bit of a cop out, is different from most Chan movies. The physical humour (from having his family jewels destroyed to popping red hot peppers into a villain's mouth) is what matters here, and there is plenty of it to keep you laughing throughout.
One of the major differences in Mr. Nice Guy is with regards to the dubbing. For once, the actors mostly speak English and their mouths move the way you would expect (as he says in the end outtakes, "I get nervous when I speak English"). For fans who are used to Chan movies, this might actually be a bit disconcerting at first, but you get used to it. The level of humour in this movie is high. Chan is charismatic as usual. I highly recommend checking this out on the big screen.