One Piece: G-8 Fortress Arc.
Holy crap, Jim, you weren't kidding about this being a well-done filler arc. Instead of introducing random who-cares-about-you characters to fill in a bunch of episodes, it actually concentrates on the main cast and gives them something to do with this new nakama dynamic they've got going on. It also spends more time developing the antagonists, the Marines, who are actually part of the main storyline, even if the specific group of Marines we're focusing on in this arc aren't canon. The main captain of this group of marines, Johnathan, is pretty excellent to watch at all times. Whenever he's on-screen, it's like a light suspense/mystery series instead of plain shounen action. Whoever wrote this filler arc needs a raise.
Really, this guy has such a good handle on the characters and their dynamic. And the main cast, even the Idiots, seem to be avoiding carrying around the Idiot Ball for plot convenience. Luffy actually seems to have a brain and manages to come up with some solutions to problems that -aren't- 'hit it really hard over and over again'. Not many, no, but at least he's getting better at knowing when to use his violence and when to let the smart people handle things. I also approve of him -actively- making a decision as Captain for the crew to go back their confiscated gold, even if it was only because it would stain a Pirate's pride to have his gold taken from him. Similarly, Nami's character seems to have been salvaged from the ultra-bitch from the previous filler (and even parts of the Skypeia Arc). Even with her kneejerk reaction to go back for the treasure, we later find out that she -does- remember that the reason she initially cared so much about money was to help people (or in this case, repair the crew's beloved ship they've had since like episode 15).
In particular, the setting is perfect for showcasing the abilities of the whole crew. Their combination of intelligent characters when stealth is needed, and powerhouse characters when they need to apply surgical force is really awesome to see in action in a "Prison Escape"-type setting. The various callbacks to previous arcs (The Waver/Dials, the trials the Going Merry ship has gone through) and the subtle setups for future plot points (Robin's intel-gathering, Luffy's declaration for adding a shipwright to the crew) really make the arc feel pretty seamless for a filler piece.
The amount of joy I get from seeing these characters act genuinely clever again cannot be described. With the exception of Zoro (and really, that suits his character), the entire cast was able to handle at least a minimum level of stealth and disguise, as befitting a group of PIRATES. I was particularly pleased that Sanji got to do this well in his cooking-centric episode, even with the burden of Luffy along for the ride (who was also surprisingly able to not blow their cover for a good 4/5 of an episode, and when he -did-, it wasn't actually his fault - the awesomely brilliant Commander Jonathan just happened to get lucky and recognize him from the wanted poster). By far the most entertaining parts of this arc has been seeing the on-the-spot acting from Usopp, Nami, and Chopper though. Usopp managed to frame a high-ranking Marine officer as being a disguised member of their Pirate crew. And Nami and Chopper... man, the scene where Chopper 'takes Nami hostage' was just hilariously brilliant. I didn't think the little guy had it in him to sound so threatening! Anyway, seeing successful ruses is always nice, and the fact that their opponent is pretty quick at figuring them out if they aren't good ruses makes it all the more exciting when they're successful.
I kinda wish that the Marines were the main antagonists more often, it is far more satisfying to watch the crew be Pirates who get the better of the misguided Marines than it is watching them just fight other Pirates... Alternately, get this director back more often.
