Blogger
Maybe Blogger's popularity (and cultlike adoration) came from the fact that it was one of the earliest and easiest blogging tools. But we like to think it was all about that cute logo. Either way, Blogger played a huge role in propelling personal publishing into the mainstream, pushing out a passel of hipster T-shirts, spawning endless imitators, and happily, paying off for creator Evan Williams when Google came along and swooped up the service.