I use a Logitech G9, I abolosutly love it to bits. I'm lost with anything else.
I'ts probably a bit lacking these days but as far as comfort, and precision goes its the business.
I must add that Logitech's Setpoint Drivers are totally useless. Sad thing is you really do need them to get the most out of your mouse. I gave up running them. As the mouse stores the profiles in its own memory, once you have it setup your way, thats it, when you use it on your laptop its the same, on your mates Pc.. you get the picture.
I always recomend Logitech's products, I've owned so many over the years, PS2 controllers, PS1 peripherals, PC products. Never had an issue with any of them.
Currently im using G11 keyboard, with a G9 mouse. Fantastic Combo.
tl;dr G9 = Awesome, Setpoint = ***.
PS. the Original FEAR game, dont like this combination of Kbd and Mouse, and refuses to work with it. so dont expect to play FEAR.