Nicky Nichols (Natasha Lyonne)
Backstory: A former heroin addict who’s part of Red's crew, Nicky talks a big game: She's acerbic, sleeps around (with both Morello and Alex), and isn't afraid to get tough with people. But she also relies on Red for emotional support, and occasionally comforts other inmates in need. (Granted, her idea of comfort is "There's always hope tomorrow will be taco night," but still.) Not to mention that Nicky is a strong contender for the show's funniest character as well.
Place in Litchfield's hierarchy: When she's running with Red, Nicky is untouchable; even when she's not, the charmingly flirty, foulmouthed inmate is still treated with respect by everyone from cellblock veterans to newbies.
Pre-OITNB: Though many have heralded the show as Lyonne's comeback, the actress — who gained fame from the American Pie movies and the indie flick Slums of Beverly Hills — has appeared in dozens of movies since her late-Nineties heyday.
Best line: "You're one Cheerio in the bulk box of life."