I'm a "limited third person" kinda gal, myself. It's easier for me to keep some mystery in the story that way. I may know everything, but I don't want my characters or my readers to! I find that if, for example we have a group of main characters, I will want to skip around for their perspectives on things, or if the group splits up for a time, I want to know what everyone's up to, but past that, I don't want to reveal anything before it's time.
I've only ever done a first person fic once, and it was only because I wanted that one character's perspective on a specific event in canon... and it was a one shot, so I didn't feel all that limited by it.