SteelSeries Sensei Pro
I've hated and loved it, hated it then loved it again.
Can't get anything that gets anywhere near as comfortable for me but I do feel it has issues with it's laser and tracking throwing a wobbler at times.
I have tried...
Logitech G502 proteus core - loved it's tracking, loved but what a stupidly large design.
Logitech G302 Daedalus Prime Gaming Mouse - again like the G502 loved the tracking/sensor but again, what a stupidly designed mouse....it has no weight and lifts to the right side during quick movement.
SteelSeries Rival - eeeeuh, what a horrible feel.
Mionix Avior 7000 - too light weight, felt no where near the premium enthusiast's mouse it's supposed to be.
I sent them all back.
My hunt continues but until then I still use my Sensei Pro but I do have a R.A.T. 5 that I hate and refuse to use. MS Intellimouse 1.1 that just feels to slow to me these days. MX518 1st edition that I've had for years and never liked as it feels cumbersome. Razer Deathadder 2013 ....why the fuss about Razer, I actually despise this mouse. It sits on my son's PC now.
I'd like to try a zowie mouse but I like on the fly DPI switching for certain games, it's just what I'm used to, so Zowie I'm swithering over.