This is the longest saga. It is interrupted by several filler arcs (noted below) that can be skipped to maintain story pacing.
Widely considered the series' peak. Watch every episode here, though some guides suggest skipping episode 33 and 50 as they are standalone filler. Watch Bleach - 005
For the best experience, most guides recommend following the canon storyline while skipping large blocks of "filler" that were not in the original manga. This is the longest saga
The modern continuation adapting the manga's final war arc. This should be watched only after completing the original 366 episodes (minus fillers). Watch every episode here, though some guides suggest
Bleach episode 5, "," is part of the initial Substitute Soul Reaper arc and focuses on Ichigo and Rukia dealing with the Hollow known as Shrieker.
Below is a long-form guide for the overall Bleach watch order, covering the original series, movies, and the continuation.