Generally, my heroes are good guys, in the sense that they’ve always been good. They may be a bit stuck up when I pick up their story, or have made a few poor choices here and there (because no one in the real world ever does that… *shifty eyes*…) but for the most part, they’re good. You know they’re the hero within the first few scenes they have on the page. And so you dig out your pom-poms and you cheer for them. 
But sometimes… Well, sometimes I like to give the bad guy a chance. I know that’s not always something that sits well with prospective readers. We (and I do include myself in this group, sometimes) want to see things in black and white. Frodo, good. Sauron, bad. Ring must be thrown into the fire. (Isildur! NOOOOO!!!) And yet, doesn’t the “bad guy” get to have his shot at redemption?
It’s a thread I’ve noticed running through some of my stories more and more. Someone screws up. Someone screws up badly. And yet, they get their second chance (or maybe it’s their third or fourth or seventeenth chance by the time we run into them.) One of my future releases, The Bride Price, features an antagonist who early readers dislike. Vehemently. Give him a moustache and he’d be twirling it. But down the road, I still plan on giving him his own story, his own shot at fixing his life and trying to make up for past mistakes.
Some people who know I plan on giving him his own redemption story are NOT PLEASED about this. Well, okay. That’s your thing. But it’s interesting how people see villains, how they want to keep them tucked into their little box of evil and not let them out to make something better of themselves.
Is it because we like to keep things clearly delineated? Good is good and bad is bad and never the twain shall meet?
Does the young woman who gives up her child for her sister to raise and takes a large sum of money in return always have to be portrayed as bad, or do we get to revisit her some years down the line, when age and acquired wisdom have perhaps changed her views and made her regret some of her previous choices? (Yes, that character will have her own story down the line, too. Believe me, I have a lot of stories in the planning stage. Probably more than I should.)
Maybe because I’ve grown older (well, slightly older… middle-age older) I like to write characters who are not perfect, who might fit the role of antagonist in one story but work their way to hero or heroine in the next. Maybe because I’ve seen people change over the course of years (and years) that I’m more inclined to reflect those alterations in personality in the fiction I produce. Or maybe I just like messing with people. That could be it, too.