As a Java developer, I use the usual 'free' (in one sense or another) tools like Tomcat, ant, Joram JMS, etc.
However, sometimes you just need commercial tools. This morning I spent an hour profiling a medium-large scale web application with JProbe. A little set up time, then banging on the web app for 30 minutes, then generating the reports: beautiful, now I know where the "hot spots" are in the system.
As a professional programmer, the other commercial tools that I use are LispWorks Common Lisp and IntelliJ Java IDE.