Now, I know that I am going against the grain here but I believe that Inuyasha falls into the category of series that had the potential for greatness but in the end ultimately flopped. I shall explain:
As a series, Inuyasha had a very strong start. There was Inuyasha the anti-hero and Kagome, the average and sensible character. Along the way, party members are added to help balance the series. From the perverted monk, to the cute shippo, and the determined demon slayer, each adds their own little "something" to the show that makes it that much more interesting. Add to that the calculating main villain, Naraku and the occasionally villain, Sesshomaru, Inuyasha had the makings of a great series. Unfortunately, a series especially one as long as Inuyasha needs something to keep it flowing. The main plot line, which is to find all the shards of a powerful jewel called the "Shikon", drags and drags. While i admire a series that can keep a liner plot, Inuyasha was ridiculous. I can tell you that after the first 30 to 40 episodes things go downhill. After seeing many MANY episodes of the cast finding jewels shards everywhere from caves to inside of trees and seeing the cast fight the constant stream of "Monsters of the Day" that are the result of the a Shikon shard or Naraku, the plots grows stale faster than an open bag of lays potato chips. And if that was not enough, the series was left completely open ended until recently. The original Inuyasha series ended with NOTHING resolved for ANY of our heroes. There is nothing worse than to end a series with the characters walking happily off into the sunset after succeeded in completing NOTHING.
Not much to say on this front. It wasn't stellar, but it wasn't bad either. The characters moved fluently, each was beautifully designed and unique, and there was not an abundant use of still shots. Not bad for a 167 episode series.
The openings were kinda catchy, the endings were soothing, and the battle music tended to motivate. Enough said.
Ah, by far the weakest link and the ultimate downfall of the series would have to be its characters. Initially, Inuyasha was the brash and overconfident anti-hero that always managed to get the job done, Kagome was Inuyasha's sense of reason, the monk while perverted was a well of valuable insight with a useful fighting ability, and Sango/Kirara was the party's backup. Oh, and Shippo.....well he was your cute element to the series. They all have their individual motivations for going after the main villain Naraku. Pretty good motivations actually.
The problem lies in the fact that throughout the series there is absolute no character growth. They don't mentally or physically learn anything. 100 episodes in, Inuyasha is still a punk that only uses one main attack move (He does gain another one but it was a long time coming), the monk's valuable knowledge becomes completely overshadowed by his comic relief tactics not to mention his one main fighting ability ends up becoming virtually useless, Kagome is downgraded to being a damsel in distress that says three main things per episode. "Inuyasha!!!", "I sense a sacred jewel shard." or "Sit!!!". And Sango/Kirara are stuck as forgettable characters that are constantly trying to save someone that cannot and probably does not want to be saved. Even the main villain Naraku, who started off as a strong villain, is eventually rendered in an unimaginative light. For someone supposedly so smart and calculating, he became predicable fairly quickly. Move around and/or make an incarnation of myself to find jewel shards and deal with the heroes became Naraku's main plot strategies. Any other villains that popped up were usually defeated in one or two 20 minute episodes (there are one or two exceptions).
The main characters never learn any new attacks (they only have one a piece) for all 167 episodes except for Inuyasha who learns two, they never get any smarter, and no new motivations are added to their quest. The main villain remains the same throughout the series and he also never goes through any drastic changes. The lack of character growth doomed this series for failure.
I was tempted to score this series even lower but its very strong beginning and promise saved it from that fate. The series had so much potential and it would not have taken very much to make this series one to remember. Giving the characters a new ability every one in awhile and tacking on maybe an addition sense of purpose would have saved this series from it fatal stillbirth. Perhaps Inuyasha's new series will be capable of taking it to the place the original could not go.