Date: May 3, 2002

Acquired for: $25 Billion

Michael Dell called it “the dumbest deal of the decade.” And after a rough stretch that consisted of terrible management from one of the worst Tech CEOs of all time, Carly Fiona, a spying scandal, and several key Compaq execs quitting—we all shared the same sentiments. But through all the tribulations, HP still achieved its goal of becoming one of the tech industry's biggest players with the help of strong hardware sales and costly mistakes made by its competitors.