As a consumer of open source libraries, my vote has to go for MIT. There's nothing wrong with Apache but I really appreciate the brevity of MIT and BSD licenses. I know brevity isn't all you should care about, but both licenses seem to have stood up fairly well over the years while being intuitive to understand. I'm no fan of custom licenses, even if their meaning seems crystal clear (like the WTFPL). Sure it's funny, but I'd rather have people using my code be able to use it with complete confidence and with minimal hassle from their legal department.