Mei Ling was a minor character in the Metal Gear Solid series, first serving as an aid to Solid Snake over the Codec messaging system.
She always gave good information, and fun little Chinese proverbs. I was sad to see her basically leave the series after the original Metal Gear Solid .
Otacon was a crappy replacement in Metal Gear Solid 2.
Rose was even worse.
At least she came back a little bit in Metal Gear Solid 4.
I was glad to see Smash Bros. Brawl include the secret codec messages with her in them.