What's in a name?

My hubby and I have been trying to decide what to name our baby that is due in March. It's a big deal to name a child. (We will call the baby a "he", since I don't want to write baby every second. We aren't finding out what we are having, so the baby is going to be nameless until delivery day!:) Anyway, whatever name we choose,is the name he will go by his whole life, and I don't want to name him something he will hate or want to change. I want him/her to be proud of their name, and love it as much as I do.
This happens a lot when I think about names for characters as well. They are like my fictional children. Their names are imprinted in my head, along with a distinct personality, that may, someday, be loved by readers everywhere. I don't want a name that will easily be forgotten, but I don't want something too off the wall, that readers will not know how to pronounce, or will think it's too old fashioned. Whatever the reason, I want their names to have a sort of spark if you will.
I actually love naming my characters, but sometimes I pick a name and it just doesn't fit, so I end up having to change it half way through writing my book. That has only happened once though, thank goodness.
So, what do you do? Do you research the name you want to pick? The origin? What it means? Or do you just think of an awesome name and run with it? Have you ever figured out that a name didn't "fit" and had to change it?