Knewton GMAT. Its an amazing online course. i am preparing for my GMAT too and i find this resource extremely invaluable.

If you don't want to spend as much, this site (beatthegmat.com) also has about 750 questions with explanations for just $99. Knewton is a full class, though, and the questions here are a guided self-study. Good luck

All major GMAT prep companies offer online versions of their courses. The majority of them have been reviewed by students such as yourself here: https://reviews.beatthegmat.com/

I'd say before you make a decision, attend a free class to get a sense of the overall teaching style and format of the classroom. I think every company allows you to sit in on a class for free - you don't have to sit in on the whole thing though, you can stay for only 30 mins and that is probably enough to make a general opinion. I personally believe that the teacher makes or breaks the course, so that's why I advise people to get a feel of the experience before they spend money.

I have heard from several friends that Veritas is very good for online material. I was looking at their site and they have many options for live online courses as well as pre-recorded courses accessible "on demand". They have a free seminar August 24th 8pm Eastern called conquering the GMAT that I am signed up for.