I just passed in the first attempt as well and agree completely, the exam simulator really helped a lot. It 'trained my brain' to think in terms of the test and how how PMI would view things. In addition to the videos and exam simulator, I followed online links to other practice tests and just did as many as I could.
I cleared PMP exam in first attempt..
For clearing this based on my experience of studying most helpful things are
1. Studying PMBOK guide once..
2. Cornelius video lessons...
3. The prep cast exam simulator....
Besides the video lessons I took, the most useful thing I felt is exam simulator.. I practiced and completed every exam and practiced based on the knowledge areas and process groups before going to the exam which is major contribution in clearing the exam.. The more we practice with exam simulator the more chance of clearing the exam... In the exam simulator the most useful thing I felt is the explanation we get for every question... It helped me a lot to understand why the answered is correct and wrong... The real time PM questions also helped me to gain knowledge in real project management and in answering those type of questions... Simply I just enjoyed the exam simulator..
Training for Project Management Professional (PMP)®, PMI Agile Certified Practitioner (PMI-ACP)®, and Certified Associate in Project Management (CAPM)®