Mahabharat is really interesting. For me it is interesting because the Pandavas initially fought for Drona but then during the Battle of Kurukshetra they fought against Drona and their great Uncle Bheeshma. The story of taking oaths and allegiances even if they were for the wrong reasons
I forgot to say the one of the mosts interesting thing about Mahabharat was that Dhritarastra (the father of the Kauravas) did not want to fight the Pandavas: he was ready to relinquish the throne.
Bheeshma and Drona too felt the Kauravas were wrong but swore allegiance to the Kingdom of Hastinapur