Pilaf Arc - 6.5 / 10
Nothing inherently wrong with this arc, but it's also nothing special. However, even if it's just an average arc, I see potential for it as a popular, long running story that it ends up being. I also think at this point of the story it's not so much a battle shonen more than it is a gag manga.
I like the gang Goku, Bulma, and Oolong all have and how they end up teaming up with Yamcha and Puar near the end for a common cause. This is back when Pilaf was a credible threat, and not just some Team Rocket esque goons, which is cool to see as well.
Some minor things I like about this too is that Chi Chi was actually a likable character here, and Roshi was actually introduced as a very powerful character at this point of the story and not just a wise and respectable character.
21st Budokai Arc - 7 / 10
This is slightly better than the Pilaf Arc. Roshi really shows he's more than a perverted old man here. He really cares about his disciples and goes the extra mile by participating in the Tenkaichi Budokai.
Kid Krillin is a really funny character and a great character to be introduced as Goku's best friend, especially since they're almost the same age. I like how he shares Roshi's perverted tendencies to an extent too, even though he grows out of them as he gets older.
Red Ribbon Army Arc - 6 / 10
This is the worst Part I Arc, and is also one of the weaker Arcs, but I at least like some of it as opposed to most of the Boo Arc.
I like the first part of it with Muscle Tower, I dislike the part with General Blue, I like the Tao Pai Pai part the best, I hate the Commander Red and Staff Officer Black part, and I like the Fortune Teller Baba ending. Also, it drags on too long as a story arc.
22nd Budokai Arc - 7.5 / 10
Tenshinhan is actually a solid character here and I would consider him Goku's rival in Part I. His actual fight with Goku was one of the best in Part I too.
Speaking of the fights, the fights are better here than the last Budokai Arc, and there is also more tension in them. My only complaint about this Arc is Chaozu, and he never really develops after this Arc either.
Piccolo Daimao - 8 / 10
Definitely the best Part I Arc. Piccolo Daimao is the most sinister villain in the story thus far, and a lot more evil than Piccolo Junior.
The start of this Saga is very dark. Krillin dying in battle against Tambourine was very depressing. Goku becomes bloodlusted after this, and rightfully so.
Yajirobe is a really cool supporting character even though he's also a comic relief character. I thought it was awesome to see just how strong he was when he killed Cymbal too.
Goku killing Piccolo Daimao was probably one of the most powerful moments in the series as well.
23rd Budokai Arc - 7.5 / 10
This is where things get crazy when it comes to power scaling in Part I, and Piccolo Daimao was already a very powerful villain.
The fights here are the best out of any Budokai Arc. It's very interesting to see how dark Piccolo used to be here, as he is quite vindictive toward Goku for killing Piccolo Daimao.
The whole God VS The Devil theme in this Arc is pretty cool too. Especially since Kami didn't consider Daimao that much of a threat, but is scared to death of Piccolo Junior's power. I think this is where Goku officially becomes the savior of Earth, as well.
Saiyan Arc - 8.5 / 10
One of the best Story Arcs in the series. Sometimes I feel it gets underappreciated too, especially compared to Freeza and Cell.
There was a sense of hopelessness in this Arc too, especially after Piccolo dies, because the Earth's Dragon Balls won't work after that happens.
I actually love Raditz, Nappa, and Vegeta as villains, and I wish Raditz and Nappa had bigger roles in the story as a whole. Vegeta was a very interesting villain, and only gets better in Freeza.
I love how Vegeta's fight with Goku here is basically an elite saiyan warrior vs a low class saiyan, as well. The Saiyan Arc Vegeta fight is actually my favorite fight in the story.
Freeza Arc - 9 / 10
This is the peak of the story. Dragon Ball doesn't get any more well written or have as many deep themes as it does in the Freeza Arc.
There's actually some good lore regarding Namek here, especially how Guru was the last of the Namekians after the mass extinction of the Namekian race.
I love the three way battle for the Namek Dragon Balls between Gohan & Krillin, Vegeta, and Freeza, Zarbon, & Dodoria, and especially how Gohan, Krillin, and Vegeta form an alliance against the Ginyu Force together.
Vegeta really shows just how battle smart he is here. The way he kills every villain besides Ginyu and Freeza is so bad ass, as well. I think it's at this Arc where he starts to view Goku as a rival too, especially when he considers that Goku might end up becoming a Super Saiyan against the Ginyu Force, and avenging the death of the Saiyan race during Goku's fight against Freeza.
Freeza is also the best villain in the entire story in my personal opinion. He is cold, cruel, and calculating, and a figure of power and hype, as well as fear. He instilled fear even among his most loyal subordinates like Zarbon and Dodoria. It's easy to tell he's even more evil than Vegeta, even if both wanted immortality.
Androids Arc - 7.5 / 10
I consider this its own Arc and the Trunks Saga to be a part of this Arc as well.
I like the timeline plot elements to this Arc, as well as the science fiction elements. It might be one of the darkest Arcs as well, since the Androids from the future actually succeed in killing the Z Fighters.
Future Trunks is a pretty good character, even if his main role is to warn the Z Fighters about their potential dark fate. I like how he has a father's complex toward Vegeta as well, to add more depth to his character.
Some of the villains were a bit underwhelming here, like Mecha Freeza & King Cold, as well as Android #19 and Android #20/Doctor Gero. Android #17 and Android #18 were better than the four previously mentioned, but they still didn't seem intimidating enough, at least as major villains. Android #16 was pretty strong though, and I believe he was evil by the Cell Games since he still wanted to kill Goku.
The Arc also ends off anti-climactically, which is actually nice for a change, since the Z Fighters usually win in the end.
Cell Arc - 8 / 10
This is one of the better Story Arcs for sure. Cell comes from the future like Trunks did and proves to be an even greater threat to Earth than Freeza, Cold, and all of the Androids.
This is the last part of the story where Piccolo is a Z Fighter, and where Krillin, Yamcha, and Tenshinhan are all relevant to the plot. This is also the last part of the story where I take the Super Saiyan transformations seriously, since Kid Goten and Kid Trunks went Super Saiyans without issue, and Super Saiyan 3 was pushing it.
Finally, I like how this is the last part of the story where the Dragon Balls are of relevance, and not just some plot device to save the Earth like in Boo. To elaborate, Piccolo fusing with Kami made the Earth Dragon Balls disappear, Dende has to replace Kami as the Guardian of Earth, and they have to hurry before Cell absorbs too many victims.
Cell is a good villain too even though he's not as good as Freeza, Piccolo Daimao, Piccolo Junior, and Saiyan Arc & Freeza Arc Vegeta. He's very obsessed with becoming perfect and is also ambitious to a fault because of that. He's also very multilayered... I actually like how he has the intelligence of Piccolo, the pride of Vegeta, the competitiveness of Goku, and the evil intent of Freeza and King Cold.
I also really like the ending of this Arc as well. Goku dies against Cell and Gohan becomes the hero of Earth after defeating Cell. Trunks also goes back to the future to tell his mother Bulma the good news, as well as killing Future #17, Future #18, and Future Cell.
Boo Arc - 5 / 10
The worst Arc in the series. What a way to end the story too. Unlike every other Story Arc in Dragon Ball, I have more bad to say about this than good.
Krillin is no longer a fighter, Tenshinhan and Yamcha fade into the background, Gohan and Piccolo became shells of their formers selves, and Trunks and Goten are the worst Z Fighters in the story.
Mystic Gohan, Gotenks, Gogeta (he was at least mentioned in the Manga), and Vegetto are all lazy attempts at fighting Boo, as well. The Kid Boo fight was more climactic than the others, but Goku had to finish the job with a Spirit Bomb in the end, which should have been forgotten at this point of the story like Kaioken.
Unlike all of the other major villains of the story, Boo also has no character depth. Fat Boo is a literal manchild, Super Boo is just a more evil version of Fat Boo, Super Boo Gotenks and Gohan Absorbed is a piss poor man's Perfect Cell, and Kid Boo doesn't even speak or have any lines.
I feel like I could go on about more of the flaws, but I might as well end it here.
