PostgreSQL keeps on adding new great stuff. It's hard to remember all the good stuff that has been added over the years.
One of the neat ones from the past is the variadic Unnest function which I believe was introduced in PostgreSQL 9.4. It's rare that I ever had to use it, but today I was handed some data where this function was just literally what the doctor ordered. I can't do anything this sweet in other databases I have used.