Ada flavoured PL/SQL.
The Java and .NET drivers, with support for advanced stuff like distributed clustered transactions and direct mappings of UDTs into source language types.
Support for nice stuff like OLAP cubes, bare metal databases and APEX provides a nice way to quickly build database frontends.
As mentioned I am familiar with PostgreSQL, and honestly other than a couple of SQL extensions that are easier to use, I don't see much value when I compare everything that is on the box, and usually at the project scale I work on (just yet another cog on the enterprise wheel), license costs aren't the biggest hurdle to care about, there are other pain points where money matters more.
Don’t get me wrong, we love Postgresql, and MariaDB, but Oracle is still a great database, with all the features and stability you could possibly want, just at a hefty price.