Sadly, Logitech stopped producing the hugely popular G9 series of computer mice. The mice sold well, and for good reason. They are durable, reliable, and overall great. Currently there are zero mice on the market that truly, 100% replaces it and all of the features it has in one package (that i know of). You can get most features in one mouse, but you have to sacrifice something.

I suggest that we petition Logitech to restart production, with new hardware, of course, on the G9 series, maybe call it G9X2.... OR make a brand new G-10 series. There are many many forums on the internet that go into new features to add to the mouse or for different variants too. A few notable ones are:

1. Have three mice, one for right handed people one for left handed people, and one for ambidextrous people.  

2. Make the mouse larger, or have a larger size available, for those with larger hands.

3. Up the DPI / potential sensitivity of the new mouse to keep up with the new mice on the market. 

4. Put much higher quality micro-switches under the left and right mouse click buttons, for hardcore gamers, the current ones (ie the old ones, at this point) were not quite enough that i read. 

The computer mouse we know and love, the G9 and G9X should be brought back to life, or at least re-produced with a new model.

PS. Be sure to keep all features that made it loveable, a must have. Don't take anything away.