A review by d6y
If the Universe Is Teeming with Aliens ... Where Is Everybody?: Seventy-Five Solutions to the Fermi Paradox and the Problem of Extraterrestrial Life by Stephen Webb

4.0

It is what it says it is: 75 individual solutions to the Fermi Paradox. They are grouped into three sections, but I'd personally liked to have just seen the best three or four in each section.