If you're a graphic novel novice, Vision is an excellent place to tip your toes into the genre. This stand-alone spin-off from Marvel's Avengers is a deep, well-told rumination on the nature of humanity---which requires zero knowledge of the superhero world it's based in. Vision, the Avenger, is an indestructible 'synthetic humanoid' whose only desire is to work his government job, raise a happy family, and seem human. Through his search for normality we see a vision* of the frailty and conviction that define us as humans; it's in the moments when Vision and his family seem to suffer 'robotic' malfunctions that they actually feel the most real.
*Phew* that was an emotionally hard-hitting synopsis there....but don't let this somber review deter you, this book is also infused with lots of humor (notably the third person omniscient narrator). Plus, no Marvel Avengers comic could go without some action sequences too. Basically Vision has something for everyone, told in a you-can-definitely-read-the-whole-thing-in-one-sitting two book series.
*a vision in Vision, ha ha see what I did there?