Well, I was gonna recommend the Razer Death Adder Elite, but they don't seem to make it any more. Maybe the Death Adder v3 or even the Essential? (The Essential is on sale for $20 on Amazon right now, it seems.) I see that the entire line is wireless now… not sure how I feel about that.
As for the why, I really like the way the mouse fits my hand, the wired Elite version has been a tank at home and at work for years now, and the only down-side I've encountered is that it comes with the lights in some stupid pulsating mode and you have to install the software at least once to turn that off. (It remembers it in firmware once you disable it though, so you can move it from computer to computer without having to disable on each computer.)