Maverick is based on the television show. I'm not sure I saw the show, though I did know things about the characters before seeing the movie version. Anyway, the movie version is really good and has a great cast.
The plot seems fairly simple at first, dealing with Maverick trying to get to a big poker game and get the last of the entry fee he ends. He keeps ending up in complicated situations though, something because of Annabelle, sometimes because of marshal Zane Cooper and other times by his own fault. Maverick is a con man, though he does have his own sense of honor about what he will and will not do. As the movie progresses, more things happen, making it more complicated. There is some action and a good amount of comedy. It is a fun, entertaining movie that is definitely worth watching. The cast of Mel Gibson, Jodi Foster, and James Garner are wonderful in their parts.
I did get a longer review posted on Epinions recently.