Gita - Bhagawad Gita and more!

There are as many sahasranamaas, as there are "Gita"s. When we say "sahasranama", it implies "Vishnu Sahasranama". Similarly, when we say "Gita", it implies "Bhagawad Gita", that which is spoken by Sri Krishna Himself. Srimad Bhagawad Gita has taken the prominence for many reasons: 

1. It was spoken by the Lord Sri Krishna Himself in the epic battle of Mahabharata, which in itself is popular
2. People can easily relate themselves with the situation that Arjuna was in
3. It covers every aspect of our lives, more comprehensive than other Gitas, and also shorter than many
4. The poetic rhythm is much easier to follow, memorize and remember 

There are many other reasons. However, the biggest reason why the Bhagawad Gita from Mahabharata has become more popular than the other Gitas is that it has become part of the "prasthAnatrayis" of the aacharyas. It has taken the "sacred" status. Even Shri Shankara says "gEyam Gita, nAma sahasram" and "bhagavad.h giitaa kiJNchidadhiitaa". Just as ganga cleanses the sins, Gita cleanses the aatma. 

So, what are the other popular Gitas?

1. Ashtavakra Gita: This is a standalone text that is not part of any larger veda, upanishat, itihAsa or purANa. It is supposedly a dialogue between King Janaka and the sage Ashtavakra. It focuses on Advaita Vedanta (non-dualism) and emphasizes the nature of the self, the illusion of the world (Maya), and liberation (Moksha). Ashtavakra Gita PDF
   
   
2. Uddhava Gita - part of Bhagavata purANa, is a conversation between Uddhava and Sri Krishna. Krishna elaborates on various philosophical and devotional topics before this departure from his avatAra.   Uddhava Gita PDF
   
   
3. Guru Gita: part of the Skanda Purana, where Lord Shiva explains to Parvati the importance of the Guru in one's spiritual life. Guru Gita PDF (श्रीस्कन्दपुराणे उत्तरखण्डे ईश्वरपार्वती संवादे गुरुगीता॥)
   
   
4. Avadhuta Gita: attributed to Dattatreya that explores non-dualism and the idea of the liberated sage, or Avadhuta, who is beyond worldly attachments. AvadhUta Gita PDF
   
   
5. Rama Gita - found in the Yoga Vasishtha and AdhyAtma Ramayana, is a dialogue between Rama and Lakshmana that focuses on nature of self and liberation. Rama Gita PDF
   
   
6. Hamsa Gita - from the Bhagavata purAna is a dialogue between Hamsa (Sri Vishnu) and sons of Brhama dealing with nature of reality. Hamsa Gita PDF
   
   
7. Vasistha Gita : also known as Yoga Vasishta, is a dialogue between Vasishta and Sri Rama, exploring topics such as mind, reality, anture of existence etc. Vasishta Gita PDF
   
   
8. Shiva Gita - from Padma Purana is a conversation betweem Lord Shiva and Lord Ramachandra where Shiva explains the principles of the universe, nature of self and liberation.Shiva Gita PDF

There are several other Gitas such as Saraswati Gita, Ganesha Gita etc. All said, learning Bhagawad Gita would suffice for this life.

Hare Krishna!