I am using Logitech G502 Proteus Spectrum to play Fortnite. It has 11 buttons, and I set walls, ramps, and floors respectively as thumb button 1, thumb button 2, and scroll wheel. This is a pretty decent mouse.
But of course, it depends on your personal preference. Some people prefer mice with fewer buttons, some prefer more. And it's also dependent upon the kind of game you play. The G502 series, for example, is pretty heavy, so it may not be suitable for people who play first person shooters.