The only book I've ever read in all my 21 years of living that, once I finished it, I immediately picked up again for a reread. Dostoevsky's last novel makes readers' hearts soar on one page and puts stitches in their sides on the next. Ecstasies of passion and agony mix with snide irony and drama so over the top you feel like you're watching the Kardashians. Achingly verosimile portrayal of a dysfunctional family, each brother's specific brand of trauma and suffering leaps off the page, making people who have experienced similar dynamics within their own families feel seen. The eldest feels the most injured, he acts out for all the world to see; the middle child suffers in silence while trying to hold the family together; and then the youngest, somewhat sheltered by his age and by distance from the abusive parent, tries his best to play therapist to issues he cannot fully understand while still being forced to watch his two elder brothers, whom he loves, destroy themselves. It is a dynamic so vital and so universal that it has not lost its relevance in 140 years and I dare to say it never will. 
And the brothers are not the only characters that shine with vivid colors and chaotic brilliance. The vivacious Grushenka, Katya proudly and willfully tearing herself apart, the pain-ridden Snegiryovs, devious Rakitin and the spiteful Smerdyakov... not one of these creatures is neglected. Each one is a joy to read about. What is their deal????
The Brothers Karamazov made my jaw drop with shock and delight in book two and only kept getting better and better from there until I was sobbing helplessly in the last chapter. And the fact that this masterpiece, this hymn to struggle and hope, this hilarious philosophical treatise WAS INTENDED AS ONLY THE PREQUEL TO A SECOND WORK THAT DOSTOEVSKY REGARDED AS THE MORE IMPORTANT ONE...I will never be over this. I am in truly Dostoevskian agonies thinking about it.