A must for DBZ fans, but too basic too appeal to hardcore gamers.
Dragon Ball Z plays like most fighters. You have a punch, kick, block and Ki-attack button. Also, each character has their own combos, most of which result in spectacular energy attacks; a key element in the DBZ universe. There isn't much more too it, and that's where DBZ Budokai's main problem lays: there isn't much depth or complexity. It's just button mashing, blocking, button mashing and using a beam attack here and there...there isn't much more too it. To make up for this though, the learning curve in Budokai isn't big, and is very accessable.
Dragon Ball Z contains a handfull of game modes. First is the story mode, which retells the story of DBZ from Saiyan saga to the Cell Games saga. For the most part, the story is told through short cutscenes with a few battles inbetween them. Most of the memorable moments from the anime are here, but the story mode's short cutscenes also make it feel very rushed, and most of the time, you'll just be waiting for the next fight, skipping the cutscenes. Then, there's a standard duel mode where two players duke it out with one of the game's more than 20 fighters. There is also a world tournament mode, where you fight in a ladder style tournament. If you win, you earn money, which you can spend buying skills, which on their turn, can help you make your own custom fighter. There's also a practice mode next to this all, where you can hone your skills, accompanied with detailed statistics. All of these game modes together create quite a good lasting value, but the game's overly basic fighting cuts into that.
DBZ Budokai looks quite nice, both on an artistic and technical level. The character looks very much like their anime counterpart, because of the great care that went into making the models. The gamecube version also has cell-shading included, making the characters look even more like their anime counter-parts. The arenas themselves are pretty nice, though maybe a bit undetailed. They are also interactive. For example, when you slam someone into a mountain, it will break appart, causing extra damage.
The game's sound is also worth mentioning. Most of the fights are accompannied by catchy, mostly hardrock themes that are nice to listen too, but get repetetive after a while. Also, every character is voiced by the same person who did his or her voice in the anime (note that the pal version has japanese voices instead).
All told, the main thing that keeps budokai from being great for every gamer is that the game is overly simple and basic. It's a nice bargain bin title, or at least worth a rent. But Dragon Ball Z fans are the ones that will enjoy it the most, since Budokai stays so close to the source material. It's a nice game, it just could've been better.