You should know what to do with this topic.
1. Haibara, Pisco and everything in between, Conan: Suddenly going from little plot to genius plot and the brilliant yet fairly simple character development is flawless. Might just be 1 because of the sudden use of awesome plot and new characters and stuff after 127 episodes but ok! Also, I like the fact that my favorite anime introduced my favorite character in my favorite arc.
2. Character Development, Conan: The plot and character development truly continued. It was without any doubt, a brilliant way to continue this series as it felt like things just kept going and things just kept getting more interesting and there was also some great character growth. I wanted to know right away where this plot was going as every little thing added to the plot added to this mystery and even though I felt that it seemed a bit too obvious, I was still fascinated by it and still thought there was a mystery here. Dark Contact I suppose should be here but honestly, some of the parts leading up to 345 couldn't even compare to the early parts of the Jodie part of the storyline.
3. Endless Eight, Haruhi: I don't have to explain this again do I? Ignoring the 6th one, this was an unusual and interesting way to do a story and it deserves to be here just because I was interested in what was going to happen, despite already knowing exactly what was going to happen. But the hilarious youtube videos and other things really made this one of my favorite arcs ever, as odd as that may sound.
4. The final arc, School Rumble: Really, if you haven't read School Rumble, read it right now. (btw: am i crazy or have the spoiler tags died?)
The ending suddenly has the story become completely serious and has tons of memorable and emotional scenes from Harima throwing his sunglasses to the heart-breaking scene of Karasuma confessing to a Tenma who he is only imagining is there. Even I cried once at that scene. School Rumble before this was typically filled with cute and hilarious moments (with the occasional serious moments) and the character development in those sillier arcs somehow lead to an amazing and emotional conclusion, which I still think is brilliant, especially considering how after reading it again, some of the silly things that happen in the earlier parts remind you of the emotional final arc. The final arc shows how because Harima was willing to give up on a relationship with Tenma in order to help her be happy, both of them end up being sad shortly afterwards, yet eventually they end up becoming more mature and I suppose "better" people. It also concludes the stories of Eri and Yakumo trying to figure out about love (mainly the fact that they are in love with Harima) which was also done extremely well.
5. Pretty much everything after volume 7 but before 17 in 20th Century Boys (but if I have to choose one part, probably the part around...I think volume 13 or 14 that lead to Friend being "killed"): Seriously the middle part of 20th century boys is an incredible mystery and conspiracy story. Shame that the last few volumes were just "ok" and 21st Century Boys was just awful.
6. Water 7, One Piece: Felt like a more epic, dramatic and interesting version of other One Piece arcs. One Piece arcs are typically awesome (and One Piece is my favorite action shonen ever) so this was even better (although I've heard Impel Down is even better than this).
7. OVER, Bobobo-Bo Bo-Bobo: This was the peak of the crazy, random humor of Bobobo. Simply put, this was the funniest part of Bobobo.
8. Ocho Introduction arc, 20th Century Boys: Yes I do realize this is the greatest coincidence ever. I loved the intro to Ocho, he was a total badass and the place he lived in just felt darker than the rest of the series where there at least feels like there's hope.
9. Chuunin Exam 3rd Exam Prelimanaries, Naruto: 15 episodes, tons of character development, fairly well done fights, lots of fun. Why can't Naruto do this all the time?
10. Clash of Red and Black, Conan: Nuff said?
