This is a very memorable spaghetti western. It has a great storyline, interesting characters, and some very good acting, especially from Rosalba Neri. Her role as the evil villainess in this film is truly classic. She steals every scene she is in, and expresses so much with her face and eyes, even when she's not speaking. Her performance is very believable. She manages to be quite mesmerizing without being over the top (not that there's anything wrong with being over the top). Mark Damon is surprisingly good in this movie too.
The music score is excellent, and the theme song is the kind that will be playing in your head constantly for days after seeing the movie, whether you want it to or not. There are a couple of parts that are very amusing. I especially like the part where Rosalba Neri undresses in front of the parrot. There's also lots of slick gun-play that's very well done.
I would probably have given this movie 8 or 9 stars if it wasn't for two things. The first being a silly bar room brawl that occurs about 25 minutes into the film. This is one of the most ridiculous looking fights I have ever seen in a movie. It is very poorly choreographed, and looks more like a dance number from a bad musical than any kind of a real fight. One might be able to overlook this if it were a Terence Hill/Bud Spencer comedy, but this is a more serious western, and the brawl really needed to be more realistic. The other thing that annoyed me about this movie was Yuma's cowardly Mexican sidekick. I guess he was supposed to be comic relief or something, but the character was just plain stupid and unnecessary in a movie like this, and he wasn't at all funny. All I can say is where is Tuco when you need him?
All that having been said, let me assure everyone reading this that Johnny Yuma is a classic spaghetti western despite the faults I have mentioned, and all fans of the genre need to see this movie.