I have really enjoyed studying the yoga Vasistha and like to read other scriptures that revolve around the same topic with the same depth to it. What are some other scriptures that fit that bill?
I know of only one scripture ,which is comparable to the YOGA BASISHTHA; that is the BHAGAWAD GITA .
In both these scriptures ,a balanced view of the four types of activities in human life--Gyana,Yoga,Karma and Bhakti , is presented.
Other scriptures ,HINDU or NON_HINDU , discuss only one or two aspects of these activities .
Religion assumes that the main objective of Human Life, is to attain Liberation or Enlightenment .Even Non-Religious activities , where material pleasure or success are main objectives , are also composed of these four activities.
There is the Moksopaya which is similar in structure and contents, also forming a dialogue between Vasistha and Rama containing roughly 30,000 Sanskrit verses (source). In fact, it was this text that formed, presumably, the foundation of the Yogavasistha. I have not read it to be sure, and as far as I know, there is no English translation available.
You might also be interested in the Shiva-rahasya-purana, available in a staggering amount of 100,000 sanskrit verses. This text is also left untranslated as of yet. There are however various English translations of the Ribhu-gita, which forms the sixth part of the full text. (source). One such example is found on archive.org. Although the Shiva-rahasya-purana is categorised as a Shaivite text, the Ribhu gita is said to expose Advaita-vedanta.
It would help if you specify the specific topics you enjoyed from this text.