5 must-haves for memorable characters

Coming up with a story idea is very easy for me. In fact, I have three notebooks and hundreds of scraps of paper with ideas for books. Many of which will never be written. Why?
I don't have the characters to bring the idea to life.
Yet.
But I live in hope that when one book ends, the universe and my personal story fairy will provide me with more characters for the next book.
Which leads me to the obvious question: How do I know which characters go with which story idea? I've come up with five character must haves for me to actually start writing the book:

1.) I have to like the characters (villians exempt, of course). Writing a book of 100K words can take six months to a year. That's a long time to spend with an imaginary someone you don't like.

2.) The character's goal has to be something in keeping with their natural tendencies. This is what's usualy referred to as motivation. I have to believe that despite the odds the character has a chance to achieve their goal--even if they don't think they can. I really love underdog characters.

3.) The characters inner conflict has to raise the stakes for the plot. For example, in my current book, one of my heroes needs to fix problems, solve things (his self-worth is dependant on what he can do for others)--he's a man of action. Yet he's facing the Plague (yes that plague) and his gun is useless, but he keeps trying and ends up making things worse.

4.) They need to have habits that reflect their weaknesses and strengths. Someone who craves order will constantly be arranging things, thiers or someone else's, especially as events spin further and further out of their control. Bonus: This will also help the reader identify the characters faster if the book is written in multiple POVs.

5.) The character's voice inside my head has to be unique. What they say MUST reflect who they are. This applies to both internal and external dialogue. My cyborg soldier from The Syn-En Solution would say, "put a magnet in your circuits" or think, must be an organic thing. Where as my human heroine would keep calling the cyborgs people. In short, a soldier would not think like a housewife, nor a doctor like a lawyer, and men don't think like women, etc.

Obviously, there's a lot more that goes into creating believeable characters but these five points are always my jumping off point. And once I have them, I can write the story they tell me (no plotting needed).

What about you? What are your character must haves?