A friend was going to send me some manga last week that he didn't want, I just had to pickup shipping. At first he quoted me $15, so I asked him if he could please send them media mail instead since it would be much cheaper. $6, and I got the package in 2 days no problems. I've never had an issue w/ mm in the 10 or so years I've been using it.
That said, I don't ship games mm anymore since you guys clarified for me that it's a no-no. I'd still send books/strat guides/movies that way tho.