I think the major ones are Christmas, Halloween, and Valentines day. Pride is becoming more popular for LGBTQ creators. And some people might do Heritage Months.
I wish the Sakura Festival was a larger holiday, but I think that is mostly just locally to where I am.
I guess other holidays...
Fathers/Mothers day, Marti Gras, Veterans/Memorial Day (tho people outside of the US may not know what that is)