What is the most highly regarded GMAT prep course?

If you really want to get success in GMAT then according to me the best way is to take part in tests as much as possible before the real exam.

There are lots of websites that offers GMAT samples. You can find out them. According to my opinion you can check www.testcircle.com, you will find there Free sample questions in free sample videos, just same as the types of GMAT questions. You will also find there audio-video solution of those questions.

In real exams timing plays a major role so if you will have an deep experience of practice tests then you will handle the situation. If you want to join a test series then I will suggest you to join examlive.com, www.testcircle.com because with test series they also provide lessons, examples and audio-video based solution of examples and the questions of test series.