Okay, so let's face it, 'filler' is one of those terms that alongside 'remake' is usually met with a negative reaction. After all, filler arcs only serve to draw out a series even more and, in some cases, they even mess with the show's continuity. However, what are some filler arcs or maybe even single episodes you guys can think of that you actually liked? For me, there are a few standouts. First one to come to mind for me is the G8 arc from One Piece. Not only does this feel more like something Oda would give us than the other arcs that preceded it, but the characters introduced here were actually really interesting. The main antagonist is especially awesome and is probably one of the most intimidating marines in the entire series. I'll even go so far as to say this felt more relevant to the series than the Davy Back Fight arc did. Another one is the Poison Six Pack arc from Kinnikuman Nisei, aka, Ultimate Muscle simply for not only giving the side characters something to do again but also giving Gazelleman that character arc he was supposed to get in the manga before the writers temporarily forgot he existed. Also, I don't know about anyone else here, but I really liked the Waking The Dragons arc from Yu-Gi-Oh Duel Monsters. I'll admit, some plot points are stupid, but then again, I expect that from this series. Otherwise, I thought this actually had a solid plot, some really good duels and for the life of me, I will never understand why people constantly mock the biker gang. I actually found them interesting for the most part. Also, it was kinda nice to see an arc that gave both Atem and Yugi significantly more development than any other story arc. (And yes, that includes season 5) Virtual World arc came close, especially for giving almost everyone something to do, but it doesn't compare to Waking The Dragons. Oh, and let's not forget Atem's duel with Dartz, which was probably the best duel in the anime. Red Noah from Nadia: The Secret of Blue Water. Yeah, this is technically a filler arc seeing as it wasn't originally part of the main story line and is a direct follow-up to Lincoln Island. And yeah, this arc is the soul reason I can't recommend skipping Lincoln Island because if viewers did do that, certain plot points here wouldn't make sense. Anyway, not only is this arc really well executed, but it also reveals the Secret of Blue Water. Kind of hard to believe this was filler considering how relevant it was despite the show's creator wanting us to believe otherwise.
There's not many anime I've seen with filler episodes, though the fillers in Fairy Tail come to mind. Most of those fillers are actually enjoyable to watch. There is a whole filler arc too with the Key of the Starry Sky, that one is alright, nothing really special. But yeah besides that most of them are fun and a little different.
I really liked the Zanpakuto Rebellion arc in Bleach. It really gave life to the Zanpakuto spirits and gave an inside view on not only the relationships between Zanpakuto and wielder, but also about the characters themselves and their motivations.
I know I'll get a lot of flak for this, but I actually like the Naruto filler. It really fleshes out the characters and helps them grow; without them, it would pretty much just be all about Naruto and Sasuke.
I loved the Tales of Ba Sing Se. Its a little filler episode for Avatar the last air bender that goes over the lives of each of the main characters. Honestly, when I think of this, this episode is filler done right. It doesn't add anything to the story, but each character gets a defining moment and we even get a deeper look into some of the other characters. My favorite and heart wrenching story was Iroh's story. First time I actually cried to an anime show.
