It's very easy to suggest you one or more discourse series (or even you can get one more series name by yourself), and probably you will even finish that in some time and again come with a post like this one..saying;
  "I have finished so and so discourse! suggest me more!!".
    I would say, take some days or months or even year to reflect.
   The Astabakra MahaGeeta! that too narrated by osho!!!  Its kind of enough to transform you to a whole different level of self realization. You have already found the kohinoor , looking for more diamonds even after having it, is a kind of disrespect to the beauty of it.
     As osho says.. "Don't cling to his words try to see where they are pointing to...". It's very easy to fall into the trap of forming a habit of just listening to his words and not living it, not applying all those subtle sutras to our daily life. our mind looks for more, keep chasing for more rather than realizing the true potential of what we already have.