Rossini once described rival composer Wagner's work as having "some wonderful moments...and some awful quarter-hours". Inuyasha, it seems, can also be described this way. It has many great episodes, but in between them are countless filler episodes. The entire series consists of about 175 episodes, of which I'd say at least 125 are filler or some sort of subplot (I didn't bother to count and I wouldn't be surprised if that number were in fact higher, though).

Some of these filler episodes are actually quite enjoyable, though many are quite silly or dull. Nonetheless, the constant digressions start to wear thin after the first few seasons as the plot ends up progressing at a labored crawl for most of the series. Character development, too, slows down greatly and by the later seasons, the cast has become quite unchanging, resulting in increasingly stale jokes (particularly those concerning the monk, who's ironic traits start out as mildly humorous but grow tiresome when the jokes associated with them appear repeatedly).

However, all of that isn't to say that Inuyasha is a bad series. It just isn't a great series the way Neon Genesis Evangelion, for example, is generally considered to be. As something to watch at the end of a hard day, it is nice, but it could never be confused with high art.