I'm looking for an Oracle database management tool like sql server management studio. I've searched the internet and found a lot of tools on the following link:
http://www.freedownloadscenter.com/Search/oracle.html.
But I don't know which one is better.
I need a stable and easy-to-use GUI tool for working on windows.
The best free ones are (in no particular order)
The best commercial ones are (in no particular order)
If you are looking for a system management tool for your Oracle database it is worth looking at the Oracle Enterprise Manager
My shop uses an open-source Eclipse plugin called SQL Explorer: http://eclipsesql.sourceforge.net/ It has good stuff for examining schemata; it integrates with your source code control system; it works on other database table servers too.
We also use a commercial tool called PL/SQL Developer: http://www.allroundautomations.com/plsqldev.html This tool has a "SQL Beautifier" which can tidy up some of the hairiest queries you can imagine. In tidying them up, it helps the one writing the query find typos. It also has a context menu that will do "EXPLAIN PLAN" on a query that's already running, and a way to stop a running query. Those are incredibly handy tools.
Carpenteri mentioned Oracle Enterprise Manager. That comes with your Oracle thick client. I find it helpful for getting an instance-wide view of what's going on in your server.
You could use a combination of some tools like SQL Developer, SQLTools and Aqua Data Studio