I watch TV. Not a lot of it. I don't have the time.  I watch it to relax, I watch it to find new ideas or new ways to build stories. I watch television like a writer: what's the point of view? what does the subplot have to do with the story as a whole? how does the event(s) affect the character? A good series will consider the main characters, some of their backgrounds, their relation to other characters and their personalities.
A great series will suck you into the world so that the characters are now your friends; people you know. you know the environment and how things work in their world. You learn the rules so you can catch mistakes and piece things together as the tale unfolds.

There is a double-edged sword that comes with that kind of intimate knowledge. Not only do you see the good and loveable side of the character, but the same person's shortcomings and frailties. You watch them make mistakes and pay for them. you suffer with them and hope things turn out for the better. It takes a tremendous amount of planning and work to turn a character from a paper doll to a flesh-and-blood person.
So with all that said, this is the point: Exactly how important is it for a writer to show the character's frailties, faults and shortcomings? Just how much realism do readers expect to find in a character? Now, I'll grant that that the answer to that question is as relative as time. For example, a character in a biographical story will be expected to portray the faults and strengths of the person who lived. There needs to be a balance between the same person's personal strengths and sins.

But in something like a romance novel, (and I'll admit that I do not read romance novels) said character can simply be a victim of circumstance and rise to the occasion or end up rescued by a future lover, ect. I do not know how realistic readers expect those characters to be.

In fantasy, there's not so much characterization involved; the character needs to be heroic, willing to take chances, willing to take the long road to attain the goal. Ultimately, it's the quest that's important. Do we need to know about the character's weaknesses or faults?  I think if it's necessary, it needs to pertain to the story.

That being said, here's the other point: In watching Supernatural I've come to notice that throughout the season, we've seen more about the characters' shortcomings and faults. I find it distracting and distasteful. Is it honestly necessary to drag the characters through the mud to make it clear that they are not perfect?
One thing that struck a note with Star Trek fans when the series came out in the 60's was how the characters were imperfect, had their moments but still prevailed as heros. You still had respect for them at the end of the episode. People involve themselves in a story to find some refreshment from the day-to-day drudgery. We read of heros to find refuge from the ugly side of humanity. After all, who wants to read a story about some ass who cheats on his wife, cheats on games with his friends, lies to his kids and won't pay for his coffee? The only reason to read about that schmuck is to wach him get his butt kicked.
Am I wrong about that?

Heros are made to inspire us, to remind us that our decisions and actions and words affect those around us. We all have monsters inside us. We are all capable of terrible brutality. We tame that inner darkness with civility, respect and empathy. But when a character, a hero, is dragged through the mud of his own sins, it takes something away from the reader, too. There's a loss of respect, a serious let-down. How can, why should we respect and love the character when the person's shortcomings, their dirty laundry, is bandied about like a bumper sticker?

This is not to say that a writer should not show the character's imperfections, but that the shortcomings and sins do not need to be emphasized. We all fail. We all screw up. But if that's all we concentrate on, there'd be a good deal more depressed/suicidal people in the world.
I'd much rather concentrate on what is good and encouraging in a character than to dwell on their sins.
Nuff said.