These stocks have helped Buffett build his legacy with Berkshire Hathaway.Many consider Warren Buffett one of the greatest (if not the greatest) investors ever. Nicknamed the Oracle of Omaha, Buffett has built a decades-long track record of investing performance, most notably through his holding company, Berkshire Hathaway (BRK.A 1.00%) (BRK.B 1.13%).You shouldn't ever mindlessly buy or sell stocks without doing your research, but I'll admit that it's hard not to glance at Berkshire's portfolio, even if onl ...