For years, anime series have been immensely popular for their Opening and Ending cinematics, and some of the companies in charge of them are known for using or "favoring" a specific artists over others.
Of these anime series, these are among the most prominent and well known that do so.
Pitch changed for some of them. You know how it is.
These guys of the "Top 5" (Fairy Tail not included):
BLEACH (viewable fully in post #6 of this thread)
Also, widely popular series: