Some Oracle professionals swear by SQL Plus, others just don’t even use it. There are a lot of tools out there for interacting with the Oracle database (and other databases as well) that serve as an alternative for SQL Plus; to name a few:
Personally, I use both SQL Plus (command line version) and SQL Navigator. Why SQL Navigator? Because that’s the standard Oracle SQL and PL/SQL development tool the company I work for has adopted. SQL Navigator is not a bad tool, with the exception of a few bugs here and there. It does make developing and debugging PL/SQL programs faster. On the other hand, I use SQL Plus for testing and running SQL scripts locally on my machine. I do think that SQL Plus is the de-facto standard for writing and executing SQL scripts because it is available with every Oracle installation. If you have Oracle, you have SQL Plus. Just out of curiosity, Do you use a third party tool to help with your database and SQL development?
Note: Check out the poll (to your right). You can even add your own answer!