I dont know how I would rank them but here are a few that ive reread recently.

Electric Cool-Aid Acid Test by Wolfe....highly recommended after reading One Flew Over the Cuckoos Nest.

The Grapes of Wrath by Steinbeck...I might have to read this one again after all the bullshit in New Orleans.

Night by Elie Wiesel....I read this a couple times a month. Short, simple but unbelievably devastating.

Crime and Punishment by Dostoevsky, Catch-22 by I forget, In Cold Blood by Capote, and most Mark Twain are all good reads.