Google typically doesn't tell us much about their algorithm or what they are looking for... but every once in a while they give us something.
They recently released a new guide on link best practices.
To save you the time (it was short anyways), I read it and analyzed it.
Here is what Google thinks is the optimal link.
PS: As a heads up, I summarize it all in the conclusion, but if you read the post you will see actual examples which hopefully sheds more light for you on what they want.
PPS: If you want my team to help you with your link building, go here.