How do I convince my parents that I should marry the girl I like? Am I sinful if I deny my parent's choice? Are they sinful if they force me?

I am 23 years old and earning good money after my graduation since 2 years. We are 3 brothers only, no sister. My parents want me to marry a daughter of my aunt, but I do not like her. Instead, I like one of the girls in my family. Both families know each other very well, and have good relationships. I have already declined marriage to my aunt's daughter, but she has no other young boy to marry in our close family, so consequently my family is sort of angry at me. I want to know: How do I convince my parents that I should marry the girl I like? They follow Islam. What stories of Islam I can convey to them? What teachings of Hazrat Muhammad (PBUH) or from Quran I can refer them about the marriage so they agree me? And am I sinful if I deny my parent's choice? Are parents sinful if they force me?